Biology - Evolution

Grade 11 - Unit 3

species

A group of similar organisms that can breed and produce fertile offspring.

Population

A group of individuals that belong to the same species and live in the same area

genetic variation

is a mutation or change in the genome of an organism

mutation

change in a DNA sequence that affects genetic information

neutral mutation

a mutation that has no effect on survival or reproduction

benefitical mutation

produce a phenotypic change that increase an organism's ability to survive. (ex. Sickle-cell allele carriers have a high resistance to malaria)

harmful mutation

reduce the reproductive success of an organism. (ex. Huntington's disease)

Describe the features of a species and what separates one species from another

-species either wont be able to mate with one another or is they do offspring isn't healthy

Explain how mutations can increase the genetic variation within a population

-Mutations are the source of genetic variation or change in genetic information. Since they have an effect as soon as they are introduced into a population as well as when they are inherited.
-Beneficial and neutral mutations are usually passed on from generation to generation, but harmful ones are usually not.

Compare neutral, harmful and beneficial mutations

All three are a source of genetic variation and is the way how nre traits are introduced into a species however...
-benefical mutations is when a new trait inherited increases the reproductive success or fitness of a species
-harmful mutations reduce the fitness
-neutral mutations neither benefit or harm the organism and it just there

Explain natural selection and how it creates change within a species over time

-environment influences change in species. (acts as an selective
-When an organism changes in order to improve its chances for survival in its environment, it is referred an adaptation.
- leads to diversity.

Explain artificial selection and how humans influence changes in species over time

-Artificial selection is used to produce new breeds or varieties of plants and animals where only desirable traits are used
- when humans use this it also reduces genetic diversity within a population.
-Some favoured traits can be linked to detrimental alleles
eg.)
Tomato plants exhibit a lot of variabilities - some are larger, some produce more fruits and some have better taste.
Over multiple seasons, farmers have selected the best seeds to use for following seasons.
These seeds cross-pollinate over time to show a variety of desired features.
However, the tomatoes with traits that are considered undesirable are removed reducing the diversity in tomatoes

evolution

process where significant changes in the inheritable traits of a species occur over time

Pelentology

study of fossils

fossils

mineralized remains or impressions of pre-existing organisms

catastrophism

theory where Fossil patterns can be explained by a series of global catastrophes (floods, volcanoes, earthquakes) that wiped out species and were replaced by new ones

Uniformitarianism (Lyell)

fossil patterns can be explained by slow and gradual change on Earth caused by weather patterns and geological forces

comparative anatomy

studying post structures of different species to understand their evolution

Homologous features are:

Same basic structure but have different functions because they share a common ancestor but modern species use them differently (suggests common ancestry)

analogous features

structure is different but have the same function ( eg. fish and whales have fins but their structure is different)

vestigial structures:

Basic structures in a body which are no more functional the way they were in their ancestral form of the trait.

embryology

embryos of more closely related organisms are more similar and imply common ancestory

Comparative biochemistry

similarity in the sequence of bases in DNA and sequence of amino acids in common proteins reflects the relatedness between two organisms

chromosome structure

-similar organisms have similar karyotypes chromosomes (DNA) from related species can hybridize
degree of hybridization corresponds to the degree of relatedness

protective resemblance

Protective Colouration (camouflage) is result and consequence of natural selection

geographical distribution

-describes the area inhabited by a population
-where the earth is decided into 6 biogeographical regions:
-Neartic
-Neotropical
-Paleartic
-Ethiopian
-Oriental
-Australian

Biogeography

Study of past and present distribution of organisms each has distinct fauna and flora, related organisms are found in the same regions and each region has animals in similar niches

Domestication

the process of changing plants or animals to make them more useful to humans

Classification

hierarchical levels of similarity reflect phylogenetic (evolutionary) relationships

Describe the work in paleontology of George Cuvier

-observed fossils and discovered:
-organisms can only exist in one layer and not resemble organisms in any other layer
The lower they are the older they are
the higher they are on the surface the newer they are
-called catastrophism → fossil patterns can be explained by a series of global catastrophes (floods, volcanoes, earthquakes) that wiped out species and were replaced by new ones

Describe the work in paleontology of Charles Lyell

-observed fossils and observed similar features
-Uniformitarianism --\>
fossil patterns can be explained by slow and gradual change on Earth caused by weather patterns and geological forces

List and describe evidences scientists use to support evolution (9)

-Paleontology
-Comparative anatomy
-Embryology
-comparative biochemistry
-chromosome structure
-protective resemblance
-geographical distribution
-domestication
-classification

use and disuse:

-structures that the species used becoming larger and stronger
-structures not in use becoming smaller and weaker
-allows species to become better adapted to their environment

inheritance of acquired characteristics:

-species becomes more complex through the process of acquired traits from parents
adaptations to environmental conditions during the organism's lifetime could be inherited by future generations
-new simple species are created by spontaneous generation

natural selection

-Natural selection preserves favourable variations within a population of organisms, while those that are injurious will eventually be eliminated

survival of the fittest

-describing the mechanism of natural selection
-in nature, there is competition to survive and reproduce

Describe the importance of the HMS Beagle in the work of Darwin

-collected observations for 20 years on anatomical differences within and between species, biogeography and fossil records
-published his theory of evolution (Theory of Natural Selection) in 1859 in the book "On the Origin of the Species"
-Provided us with new evidence on the origin of species and the theory of natural selection ( preservation of favourable variations within a population of organisms)

Describe how competition between and within species can impact population size and adaptations

comeptition for resources and survival act as a selective pressure where only individuals with the most favourable adaptations, (better at surviving and reproducing) are naturally selected. Those who have not adapted these traits will essentially die off reducing population size, and as the individuals with more favourable adaptation produce more offspring, the favourable adaptation will become more common in the population.

directional selection

-A type of natural selection, environmental changes or migrations to new locations
- selection favours one extreme of a trait and overall frequency shifts towards that trait

stabilizing selection

-occurs once a species becomes adapted to an environment
-selection pressure maintains those traits and eliminates extremes
-Is like "Getting rid of the ends"

disruptive selecion

-favours individuals at either extreme for a trait and intermediates become less common
-important mechanism for speciation

sexual selection

A form of natural selection in which individuals with certain inherited characteristics are more likely to mate than others
- often leads to the males and females of a species evolving appearances and behaviours that are quite different from each other.
-through female choice and Male vs. male competition

genetic drift

genetic drift is a small change based on luck that can cause major changes in the environment.

genetic bottle neck

change in allele frequency as a result of dramatic reduction of population size, occurs as a result of a natural disaster

founder effect

-change in allele frequency because of a new small population is established
- is a type of genetic drft and usually occurs on island populations
-small population separates
- human influences on selection

Human influence on selection:

-harvesting techniques
ie.) hunting "prize animals" results in populations with fewer or smaller desirable traits
habitat
-destruction/ invasive species
ie.) causes many deaths within a species resulting in populations with low genetic diversity
-climate change
ie.) birds are changing migration patterns resulting in changes to their environment
-antibiotics
ie.) increase the number of resistant bacteria resulting in stronger populations of bacteria

Describe the three types of natural selection

-disruptive → selection favours individuals at either extreme for a trait and intermediate is less common (Middle is gone) *important for speciation*
-stabilizing → species becomes adapted to an enviroment and selective pressure maintains those traits and gets rid of the extremes (getting rid of the ends)
-directional→ environmental changes or migrations to new locations
-selection favours one extreme of a trait and overall frequency shifts towards that trait (move over)

describe sexual selection and sexual dimorphisms

-sexual selection is where one trait increases the mating success of an orginism
-sexual Dimorphism (di mean 2 and morph means option) is when the two sexes of the same species are different from eachother (ie. Male birds of paradise are flasy while females are brown)

compare natural and sexual selection

They both cause species to evolve new traits in order to increase fitness however...
-Natural selection favours the reproductive success of individuals with certain traits over individuals with other traits and happening through stabilizing, directional, or disruptive selection selection
-Sexual selecion is a subcategorey of natural selection wherre one trait is favoured since it enhances the reproductive success of an individual and happens through femal choice or male vs. Male competition

explain how small populations can experience evolution without selection pressures

Happens though genetic drift, genetic bolleneck, founders effect and does not happen because of selection pressures/ natural or sexual selection since it is based on luck

microevolution:

-evolution occurring at the species level where natural selection and other selective mechanisms drive the evolution of a new group of organisms

speciation

the formation of new and distinct species in the course of evolution.

reproductive isolation:

any behavioural, structural or biochemical trait that prevents an individual from one species from reproducing successful with another species

-prezygotic

mechanisms that prevent mating from occurring or prevent a gametes from meeting (ecological, temporal, behavioural, mechanical)

postzygotic

Issues occurs after members of two different species have mated and produced a zygote (offspring either die before brith, do not live long or are infertile) . zygotic morality hybrid inviability, hybrid infertility.

allopatric speciation

The formation of new species in populations that are geographically isolated from one another.

sympatric speciation

The formation of new species in populations that live in the same geographic area

adaptive radiation

single species evolves into a number of different species, occurs when new resources become available

coevolution

Process by which two species evolve in response to changes in each other

evolutionary arms race

Predators and prey co-evolve adaptations for prey capture and predator avoidance due to their strong evolutionary influence on one another.

divergent evolution

species adapted from a common ancestor to different environments

convergent

species that are distantly related developing similar features to adapt to their similar environment

compare allopatric and sympatric speciation

Both allopatric and sympatric speciation create new species however...
-Allopatric speciation occurs when teo populations are separated geographically while
-Sympartic speciation happens when teo populations split into separate gene pills but continue to share a similar location

describe mechanisms of reproductive isolation

There are two types of reproductive isolation; postzygotic (after the zygote) or prezygotic (before the zygote)
Prezygotic are factors that prevent mating or gametes from meeting. This is done through: ecological, tempral, behavioural, mechanical, gametic while Postzygotic isolation is a mechanism that causes issues in the embryo like infertility, stort life span, or embryo death

ecological isolation (prezygotic)

species live in the same area, but they occupy different habitats and rarely encounter each other

temporal isolation (prezygotic)

Species dont mate because peproductive cycles are different

Behavioural isolation (prezygotic)

species dont mate because they have different mating rituals

mechanical isolation (prezygotic)

structural differences in reproductive organs that prevent fertilization

gametic isolation (prezygotic)

sperm and egg are incompatible (specific biochemisty that prevents fertilizaion)

Zygotic morality (postzygotic)

species mate but embryos aren't fully carried to term

hybrid inviability (postzygotic)

here species mate but babies have a short life span

hybrid infertility (postzygotic)

Where offspring can survive but are infertile

compare convergent and divergent evolution

Both are macroevolution show the way how a species have adapted/ evolved because of its environment however...
convergent evolution is when happens causing distantly related species to have similar features
Divergent is where they share a common ancestor but have separated/ apart different ways because of their environment

Explain how species can evolve together

-through co evolution
-where one species evolves because of of the evolution of another species
-increases symbiotic relationships between 2 species (evolutionary arms race (ie. newts have adapted to prodiced more poisin to prevent getting eaten by garden snakes however snakes are prodicing more resistance to combat this)

Macroevolution

large-scale evolutionary changes including the formation of new species and new taxa.

Synapomorphy

Two groups that share a recently derived trait

mass extinction

event in which many types of living things become extinct at the same time

transitional forms

how one species looked before it developed into another species and the step is preserved through the fossil

explain how life on Earth has evolved over billions of years

-Took more than 2 billion years for eukaryotic organisms to evolve and another several hundred million years for multicellular life forms to evolve.
-Earth's history is divided into 5 eras based on dramatic changes in fossil records caused by mass extinctions.
-Mass extinctions are often followed by an "explosion" of diversity.

explain the progression of complexity of life

-evolution is the leading force behind the complexity of life since organisms need to adapt enable to survive and reproduce
-these adaptions allow species and populations to diversify therfoew allowing each organism to be more complexcompared to generations before

Homo habillis (handy man)

-regarded as the first true human
-oldest fossils on homo

Homo erectus

-lived alongside australopithecines
-discovered with evidence that they used fire and tools
-earlier form of humans
-about 5 feet tall

Homo neanderthalensis

-shorter more powerfully built skeletons \> helped them keep warm in northern Europe
-skilled at making tools, performed burial ceremonies and may have been capable of complex speech
-Neanderthals died out because they did not evolve/adapt

Homo sapiens

A species of the creatures Hominid who have larger brains and to which humans belong, dependent of language and usage of tools.
-evolved in Africa and then migrated to other continents

Anthropoids

-Early primates could've evolved anthropoid organisms
Have:
-Large brains -Diurnal activity (awake during day and sleep at night)
-Live in social groups
-Provides lots of care for their young
(ie. monkeys and humans)

Hominid

-specied that decend from most common ancestor of chimps and humans
-have Nostrils (close together, directed forward)
and No tails

Primates

An animal order including monkeys, apes and humans --\> large brained mammals, forward directing eyes, flexible feet/hand, thumbs can touch ther fingers and can curl to grip

compare primates and hominids

describe the features that make humans different from other primates

-Reduced brow ridges
-Reduced sagittal crests
-Small teeth size
-Flat jaw angle

describe how hominids have evolved and travelled

Evolution
-have nostrils close together directed forward nostrils
-no tail
-bipedalism

George Curvier

-observed fossils and found that orginisms only exist in one layer where complex orginisms were found top while simple were found at all depths and that
-Developed the theory of catastrophism --\> fossil patterns can be explained by a series of global catastrophes that wiped out species and were replaced by new ones

distinctly human features

Reduced brow ridges
Reduced sagittal crests
Small teeth size

A aferensis - Lucy feat.

-Bipedal motion → hips started to change for balance and holes in the back ot your head
-1m tall
-Large canine teeth
-Small brain

H. habilis feat. (handy man)

-first hominid
-lived alongside australopithecines
-regarded as the first true human

H. erectus feat.

-human like feet and hand bones
-smaller teeth
-fully bidpedal
-about 5 feet tall
-discovered along with evidence for the use of fire and tools

H. neandethalesis feat.

-shorter more strongly built skeletons
-combined scavenger and hunter-gatherer
-skilled at making tools
-performed burial ceremonies
- may have been capable of complex speech

difference between prosimians and anthropoids organisms

-early prinates evolved into wither prosimians or anthropoids however
-prosimians:
Very large eyes,
Nocturnal activity,
Long tails
(ie. Lemurs, Tarsiers)
-anthropods:
Large brains,
Diurnal activity ,
Live in social groups,
Provides lots of care for their young (ie.
Monkeys, Humans)

evolution of humans

-H. habillis (first homo) evolved into H. errectus
-H. erructus evolved into H. neanderthalisis and H. sapiens

Darwin

-formulated theory of evolution by natural selection (1809-1882)
-preserves favourable variations within a population of organisms, while those that are injurious will eventually be eliminated
Survivial of fittest:
-a way of describing the mechanism of natural selection
-in nature, there is competition to survive and reproduce