EXAM 3 LO

Identify adaptations that support aquatic life.

• Adaptations in evolutionary body plans

  • Radial, Bilateral, Asymmetric

• Ability to use O2 underwater

  • Gills, Diffusion, Lungs

• Mobility in a thick/gluey environment

  • Streamlined body shapes

  • Fins for locomotion

• Different feeding/predation strategies

  • Evolution of predation strategies due to Cambrian Explosion

Explore traits of basal invertebrates.

• Sponges (Porferia)

  • LACK TRUE TISSUES, no mesoderm

  • Asymmetrical body plan

  • Sessile as adults and sedentary as juveniles

  • Specialized cells for diffusion

• Coral,Jellies, Anemones, etc. (Cnidrians)

  • Radial symmetry body plan

  • No mesoderm, only ectoderm and endoderm

  • Specialized cells for function, sac-like structures for gastrovascular activity

  • Sedentary can move

  • No cephalization, only body

Examine the diverse body plans of mollusks.

• Gastropods:

  • Snails, Slugs, Nudibranches, etc.

  • Have a foot for mobility and movement

  • Have a thick spiral mantle for protection and structure

  • Bilateral symmetry

  • Radula for scraping, chewing, and biting as they have no mouth

  • Has coelomate with hemocoel for gas exchange and absorption of nutrients (open system)

• Bivalves:

  • Clams, Oysters, Mussels, Scallops, etc.

  • Have no foot for mobility but some have a retractable foot similar to it for movement

  • No distinct head

  • Bilateral symmetry

  • No nervous system or complex organ system

  • Have coelomate with hemocoel for gas exchange and etc. (open system)

  • Capture food through gills as they have no radula, filter feeders

• Cephalopods:

  • Octopus, Squid, Nautilus

  • Radial Symmetry

  • Well-developed sensory organs

  • Most complex and advanced of mollusk group

  • They’re hunters and predators

  • They have multiple appendages that aid in movement of water through jet propulsion expelling water through mantle cavity and explleing it

  • Closed system so they don’t have coelomate with hemocoel instead actual vein-like structures to distribute fluids

Describe the four key traits of all chordates.

• 1: They all have a notochord which aids in skeletal stability of chordates and mobility

  • Most similar to a spine in tetrapods

• 2: They have pharyngeal slits and clefts

  • These are gills in aquatic animals while in tetrapods adults lack slits/clefts

• 3: The presence of the dorsal hollow nerve chord that functions in the creation of CNS of aquatic chordates, it’s derived from the ectoderm

• 4: The presence of a muscular post-anal tail that functions in stability and locomotion of aquatic chordates, humans had one when they were fetuses but lost it

Compare common traits of early chordates.

• All chordates derived from a common ancestor with a head with 3 pairs of sense organs and a vertebral column

• Lampreys and Hagfish branch off into their own sista taxa as they’re both jawless and lack appendages and the retainment of their notochord during adulthood as they have no backbone

• The first clade consists of Cartilaginous fish, Ray-finned fish, Lobe-finned fish, and Lungfish that all share the trait of having a Jaw and 2 pairs of appendages

• The second clade consists of Ray-finned fish, Lobe-finned fish, and Lungfish that all share the trait of having a bony skeleton

• The third clade consists of the trait of having lobed fins with Lobe-finned fish and Lungfish

  • Ray-finned fish develop their trait of rayed fins differing from the other two fish

Consider the evolution of jaws as a driver of vertebrate diversification.

• The hypothesis on jaws was that: They developed from skeletal rods supporting gill slits

• They both have the same morphology and come from the same embryonic cells , but there’s still not enough conclusive fossil evidence to add truth to this claim

  • This allowed organisms like sharks to adapt to becoming predators as their jaws consist of sharp mineralized teeth

  • Organisms like ray-finned fish became the most diverse group of chordates after with the development of jaws and other factors aiding in their persistence and adaptability in different environments

• The evolution of jaws not only facilitated predation but also led to significant changes in feeding strategies, enabling these species to exploit a wider range of food sources.

Understand the impact of plants on ecosystems, species interactions, and human life.

• Plants are a diverse group of multicellular autotrophic eukaryotes

  • They’re a monophyletic group driving from a common ancestor

• They can function as decomposers, oxygen producers, and in nitrogen fixtation

• Plants are primary producers in ecosystems which a bottom-up effect on the chain if their role in an ecosystem was modified

Explore adaptations required for terrestrial life in plants.

• For plants to adapt to terrestrial life they needed several important adaptaions:

  • They needed to develop a waxy cuticle to aid in desiccation and water loss

  • Use of stomata to aid in gas exchange which also helped in maintaining water loss during photosynthetic processes

  • The use of flavonoids as a “sunscreen” against harsh sunlight

  • The relationship between mycorrhizae a fungi that helped plants in sufficient nutrient access and uptake, functioned almost as roots

  • The use of spores for reproduction and early dispersal by wind

Examine the transition from non-vascular to vascular plants.

• Bryophytes (seedless nonvascular) 470 MYA

  • Lacked vascular tissue for nutrient uptake, limits the size of these plants to shrubs

  • Reliance on damp environment water for sperm to swim through for reproduction

  • The use of rhizoids for anchoring rather than mycorrhizae

  • Lack of leaves and roots

  • Mainly haploid life plan, limits genetic diversity and variance

• Traecheophytes ( seedless vascular plants) 450 MYA

  • Had vascular tissue for nutrient uptake, increased size to big structures

    • Xylem: specialized in water transport and uptake through the help of lignin in cell walls

    • Pholem: specialized in the distribution of sugars, amino acids, etc. for plant growth

  • Sperm can move w/o the dependence of water

  • Have leaves and roots

  • Mainly diploid life plan, more diversity and variance

Analyze the evolution of seeds, flowers, and fruit and their role in plant diversity.

• Angiosperms ( seed vascular plants) 360 MYA

  • Use of seeds which are embryos protected by maternal tissue and w/ food supplies

  • Flowers are angiosperms with specialized shoots and modified leaves

  • Flowers attract pollinators, pollinators take pollen aiding in dispersal

    • Mutualistic relationship

  • Pollen protects male gametes

    • Gametophyte makes pollen, gamete is surrounded by pollen wall

    • Doesn’t require water for sperm reproduction, allows for more genetic diversity

  • They have fruits which are mature embryos, aiding in dispersal

    • Fruits develop from ovaries and contain seeds that protect the embryo and provide nutrients, ensuring successful germination and establishment of new plants.

  • Flowers and Fruits are under mutualistic selection from animal

Examine how the evolution of seeds, flowers and fruit increased plant diversity

• Seed plants aid in increased plant diversity compared to seedless plants in two particular aspects:

  • Dispersal: Seed dispersal allows for increased range and habitat variance

  • Pollen: Pollen allows for increased genetic recombination with other plants which seedless plants lack

• Gymnosperms

  • Seed plants lacking fruits

  • Spores are enclosed in reproductive structures

  • Pollen protect gametes

  • Lack mutualistic relationships with animals for dispersal

• Angiosperms

  • Flowering plants

  • Embryos are protected within seeds against harsh conditions and provide food

  • Mutualistic relationships with animals

  • Fruits are mature embryos

Review transitions in plant groups over time

• 360-300 MYA : Seedless non-vascular plants (Bryophytes) dominated

  • Trees couldn’t properly decompose, turned into coal

  • Cellulose hadn’t evolved yet for protection

• 300-250 MYA: Gymnosperms (Tracheophytes) dominated during this time

• 250-65 MYA: Angiosperms dominated in temperate/moderate climates

Consider the role of plants in your daily life

• Plants have a primary role in biomes as they function in key processes such as photosynthesis and cellular respiration

• In ecosystems plants are primary producers that can cause bottom-up processes if it’s role were to change greatly

• Plants function in producing oxygen and nitrogen back into the atmosphere and up-taking CO2

• Medicinal Uses of Plants:

  • Pain Management: Opioids from Poppy, Aspirin from Willow, Oxycodone from Opium, and Morphine from Papaver somniferum

  • Cancer Treatment: Taxol from Pacific Yew and Vincristine from Madagascar periwinkle

  • Cardiac Uses: Digoxin from Foxglove

Investigate how mycorrhizae improve plant productivity

• Mycorrhizae is a fungi that has a mutualistic relationship with almost all plants

  • It functions in efficient nutrient uptake allowing for increased growth of plants

  • Uptake in carbohydrates like phosphorus by mycorrhizae allows for increased growth

  • Theres 2 Types:

    • Arbuscular: Penetrates root cell of plants for nutrient uptake

    • Ectomyocorrhizae: Doesn’t penetrate root cell of plants but forms a mantle around root surface for nutrient uptake

    • They both function in providing nutrient to plants in normal weather conditions and harsh weather conditions

Explore how plant-animal mutualisms support plant success

• Plant-Animal mutualism function in mainly dispersal of seeds and pollen

• Animals help improve dispersal as seeds (plant embryos) are carried to created distances increasing range and creating habitat variance for a plant species

• Pollen is dispersed by animals mainly pollinators that increase genetic recombination by carrying pollen of one plant species to another creating increased mating success

• Climate changes can affect plant-animal mutualistic relationships such as warmer weather that can dsirupt the flowering of plants and emergence of pollinators and avaliability of food/resources during certain climates cuasing certain relationships to end or be strained

Describe how herbivory had led to diverse plant defenses

• Herbivory can lead to the development of physical or chemical adaptation of plants

  • Ex. Some plants have spikes or thorns to deter herbivores

  • Ex. Some plants have toxins or are poisonous when consumed to deter herbivores

• Some plants develop mutualistic relationships with bodyguards to protect them from herbivores and other attacks

Understand the challenges posed by the transition from water to land.

• Adaptations to managing water loss in organisms

• Adjusting to increased UV light in aquatic organisms

• Evolving gas exchange adaptations for respiration and breathing for being on land

• Adapting to gravity on land, gravity in the water is less since water has buoyancy

• The shift from external reproduction to internal to prevent eggs and sperm from drying out

• Characteristics/Traits that allowed for survival on land

  • Exoskeleton

    • Protective hard outer covering that aids in reducing water loss and provides structural support for the organisms

  • Gas Exchange Strategies

    • Specialized structures for gas exchange when in dry areas

  • Reproduction Strategies

    • The shift to internal reproduction for success of reproduction on land

Define characteristics of arthropods, the largest animal group.

• Arthropods have certain defining characteristics:

  • Exoskeleton made of chitin or protein/calcium, but can limit mobility

  • Jointed Appendages allowed for more flexibility and movement

  • Sensory Organs such as antennas for sensing the environment , feet that taste, and well-developed eyes

  • Coelomate with hemocoel being the main body cavity

  • Open circulatory system with hemolymph in the hemocoel

  • Respiration is either carried out by “book lungs” or tracheal systems for gas exchange of O2 directly to tissues

Explore examples of non-insect arthropods.

• Crustacean

  • Ex. Shrimp, Lobsters, Crab, etc.

  • Mainly aquatic animals except for (rolly pollies)

• Chelicerata

  • Ex. Spiders, Ticks, Mites

  • All are carnivores or parasitic organisms

  • Have 6 pairs of appendages, 8 legs total

• Myriapoda

  • Ex. Centipedes and Millipedes

  • Millipedes have 2 pairs of legs each segment

  • Centipedes have 1 pair of legs each segment

Examine factors contributing to diversity in insects.

• Arthropods are the most diverse species on earth over 2.2 million species

  • Beetles are the most diverse 350,000

• Shared Characteristics for All:

  • Body Plan: 6 legs, and most are capable of flight

  • Metamorphosis:

    • Incomplete: Young larvae resemble Adults, most are wingless

    • Complete: Young larvae are phenotypically different from adults, with differences in diet, habitat, and behavior

  • Internal Reproduction: The shift to internal reproduction allowed for more success on land

  • Asexual Reproduction: Still present in certain animals but leads to less diversity and ability to evolve, though some animals have developed just fine.

Consider the ecological impacts of insects.

• Voracious Herbivores

  • Can cause famine in crops and decimate fields causing famines

  • Increased resistance to pesticides could pose a dangerous problem in the fututre

• Voracious Vectors

  • Mosquitos can cause viruses such as Malaria, Zika, West Nile, etc.

• Pollinators

  • Contribute lots of money to our economy by pollinating fruits and the production of honey, a very lucrative

• Pest Controllers

  • Some carnivorous and parasitic insects control herbivores in crops and reduce pest populations

• Decomposers

  • Some insects function as decomposers contributing to the nutrient cycling of CHON

Comprehend evolution of jaws and its influence on vertebrate diversification.

• Jaws were an evolutionary innovation when it first emerged leading to it’s rapid diversification in organisims

  • It’s hypothesized that they emerged from the bones of arches that supported gills in pre-historic fish

  • The data to support this is that both jaws and the bones have the same embryonic cells yet there is still not enough conclusive evidence to support this

• Jaws house teeth of all shapes and forms that can be used for cutting, grinding, ripping, or even be toothless having bristle-like projections

  • Sharks have jaws with rows of mineralized teeth, these were modified and adapted for hunting

  • Ray-Finned fish the most common fish have normal mineral teeth yet they’re not used in the same way sharks use theirs for hunting

Investigate the transition of vertebrates from aquatic to terrestrial environments.

• The Lungfish and Coelencath (Lobe-Finned Fish) had structures in their fins that functioned sort of like wrists, they’re they’re the oldest relatives to tetrapods currently

• The Tik-Talikk was a pre-hisotric intermediate between a tetrapod and fish

  • It could “walk” on land for brief periods to look for food but it primarily resided in water

  • It had a more defined structures of limbs such as appendages and neck to support itself on land

  • It exhibited breathing through gills and a almost lung-like structure

Explore adaptations that enabled vertebrates to thrive on land.

• The transition from aquatic to terrestrial enviornments involved various factors most notably:

  • New modes of movement:

    • Fins aren’t effective on land, need to develop strong stable appendages

  • The redevelopment of the skeletal body:

    • A strong skeletal body needed to emerge to support the weight of gravity on land as compared to in water, water has buoyancy land does not

  • New modes of respiration:

    • Gills don’t really work on land need more efficient ways of respiration like cutaneous breathing, thoracic breathing, lungs

  • Ways to prevent dessication:

    • The most important factor was preventing water loss when on land

  • Other Adaptations:

    • Shift to the Amnitoic Egg and internal fertilization rather than external

    • New modes or respiration such as thoracic breathing

    • Change of skin to dry scales made of keratin to retain water helped the move further onto land

Describe adaptive advantages of the amniotic egg.

• Amniotic egg was the shift to internal fertilization rather than external fertilization that is more common in amphibians

• Reptiles exhibit incomplete metamorphosis due to this aspect of development meaning their young resembles an adult version

  • The Amniotic Egg has several key features that helped protect the embryo inside:

  • The Hard outer shell protects the softer internal structures from harsh weather and predators

  • The Albumin helps in providing nutrients to the embryo along with the yolk sac

  • The Allantois helps in waste excretion and collection for the embryo

  • The Amnion is the fluid like substance the embryo is protected by

  • The Chorion aids in gas exchange for the embryo allowing it to “breathe”

Identify examples of amphibians and reptiles.

• Amphibians:

  • Ex. Frogs, Salamanders, etc.

  • Complete Metamorphosis

  • External fertilization, no amniotic egg

  • Cutaneous breathing or Buccal breathing

  • Primarily in tropical, humid habitats

• Reptiles:

  • Ex. Crocodiles, Alligators, Komodo Dragons, Birds

  • Incomplete Metamorphosis

  • Internal fertilization, amniotic egg

  • Thoracic Breathing

  • Have a variety of habitats whether tropical, mild, or dry

  • Predators, mainly hunters

Explore the derived traits of mammals and primates: Identify unique traits that distinguish these groups.

• Derived traits of Mammals:

  • Mammary Glands, Hair, Extended Parental Care, Endotherms, Various teeth Structures, Larger Brain Capacity

  • Monotremes: don’t have any nipples, lay amniotic eggs, Ex. Platypus, Echidna

  • Marsupials: have partial embryo development internally, then fully development is completed externally in pouch Ex. Koalas, Kangaroos

  • Eutherania: have complete uterus embryo development, longer gestation times Ex. Mammals, Humans

• Derived traits of Primates:

  • Opposable thumbs, Larger skull than jaw, forward-facing eyes for better hand-eye coordination, Hands for gripping and grasping

• Derived traits of Hominins:

  • Bipedalism, Larger skull and much smaller jaw, smaller teeth, Larger brain capacity, tool usage, Cultural and Societal interactions

Examine the evolution of early hominins: Understand the timeline and defining characteristics of early human ancestors.

• Earliest Hominins appeared 6.5 MYA

  • More upright than apes and had less canine teeth

• Australopiths appeared 4-2 MYA

  • Fully Bipedal and had more human like hands and feet

• Homo Erectus appeared 1.8-.2 MYA

  • Tool Usage, Migrated out of Africa, Used fire to cook, Much taller: 5-6 feet

• Homo neanderthals appeared 400,000- 40,000 YA

  • Habitats were Europe and Asia, Had a stocky build with pale skin, They adapted to colder climates

• Homo Sapiens appeared 200,000- Present

  • Specialized tool usage for hunting, Great dispersal to other areas of the world, Larger brain capacity that others, Cultural and Societal intellect, Much smaller jaw and larger brain

Define unique traits of Homo sapiens: Focus on traits that have contributed to human success.

• Homo Sapiens had a variety of traits for success:

  • Specialized tool usage for hunting and cooking

  • Had large brains and smaller jaws with various teeth housed

    • Had a lighter skeleton which allowed for quick movement

  • Dispersal to different allowed adaptions to various climates

  • Creation of more stable shelters allowed for longer lives and safety in environment

  • Development fo societal customs and cultures helped foster “humanity”

Consider why Homo sapiens have been so successful: Explore social and cultural factors influencing success.

• Homo Sapiens indulged in lifestyle changes, dispersal, and fostering interconnectedness with their people to develop a sense of “humanity” allowing them to outcompete and outlive other species which is why we’re the most extant and successful.

Explore the value of biodiversity

• Biodiversity has several values to our society:

  • Intrinsic Value: We think biodiversity has important ties to religious and spiritual practices and we enjoy the aesthetics of it

  • Ecological Value: Helps protect ecosystems from invasive species, and natural disasters, and maintains the ecological balance of all organisms fostering productive and rich biomes

  • Economical Value: Biodiversity is a very lucrative business as it provides us with products such as honey, fruits, vegetables, milk, and many other important cultivations

Define ecosystem services and their economic implications

• Ecosystem Services: What nature can do and provide for us in terms of aesthetics, ecologcially, and even economically

  • Aesthetically: Hikes, Trails, Shade under Trees, Picking Flowers, Beaches

  • Ecologically: Clean water, nutrient-rich soil, Species richness, Pollination

  • Economically: Products, Restaurants, Resorts, etc.

• We usually don’t realize the economic worth of biodiversity as it’s hard to put a price tag on it until it’s gone and we can’t use that resource anymore

Identify and discuss threats to biodiversity

• Threats to Biodiversity include:

  • Habitat Loss

  • Pollution

  • Global Warming/Change

  • Overexploitation

  • Invasive Species