ENVS 200: Midterm Review (Key Terms)

Natural Selection

Process by which organisms better adapted to the environment tend to survive and produce more offspring than others

Evolution

Change overtime, in the heritable characteristics of a population of species

Heritable Variation

Generic differences between organisms that allow for e.g. different hair colour, height

Fitness

Describes the success of indivudals in the process of natural selection

Common Garden

Experiment comparing populations under identical environmental conditions

Hybridization

Production of offspring sharing the characteristics of two parents

Reciprocal Transplant

Experiment introducing organisms from each of two environments into the other

Industrial Melanism

Black or blackish forms of species of moths and other organism have come to dominate populations in industrial areas

Coevolve

Two things influence each other in the process of development or evolution

Species

A group of organisms that, if they could (even potentially), breed to make viable and fertile offspring

Speciation

Group within a species separates from other members of its species and develops its own unique characteristics

Pre-Zygotic Isolation

Prevents the fertilization of eggs

Post-Zygotic Isolation

Prevents the formation of fertile offspring

Allopatric Speciation

Population is divided by something (could be quick or long-term), because there is a barrier, they can only breed internally within their groups, because of selection pressures and random genetic drift, they become separated and if they ever join back together, there will not be breeding between the species

Sympatric Speciation

Occurs when there are no physical barriers preventing any members of a species from mating with another and all members are in close proximity to one another

Endemic

Unique to a geographic location

Conditions

Physicochemical features of the environment (e.g. temperature, humidity, pH, salinity)

Resources

Things consumed by organisms in the course of their growth and reproduction

Response Curve

Physiological responses in organisms

Thermophile

Type of organism that thrives at relatively high temperatures (above 60 degrees Celsius)

Chilling Injury

At body temperatures a few degrees above zero degrees Celsius, organisms may be forced into extended periods of inactivity and the cell membranes of sensitive species may begin to break down

Photoperiod

Most widely used external signal – the length of the period of of daylight within the daily cycle

Diapause

Dormant phase in which development is suspended and metabolic activity is massively reduced

Acclimatization

Conditions may trigger an altered response to the same or even more extreme conditions

Ectotherm

Rely on external sources of heat to determine the pace of their metabolism (includes invertebrates, amphibians, reptiles, and most fish)

Endotherm

Regulate body temperature by producing heat within their body (birds and mammals)

Acidophile

Microbial specialists that thrive in environments that are highly acidic

Photoinhibition

Rate of fixation of carbon decreases with increasing radiation intensity

Avoider

Plants that avoid the problems

Tolerator

Produces long-lived leaves that transpire slowly

Deciduous

Tree species that lose all leaves for at least 1 and usually 2-4 months or more each year

CAM

Plants that open stomata at night and absorb carbon dioxide and fix it as malic acid

Autotroph

AKA Primary Producers; Major resources are photosynthetic radiation, water, nutrients, and carbon dioxide

Heterotroph

Unpack the organic packages, metabolize, and excrete same of the contents (mostly as inorganic nutrients, carbon dioxide and water)

Chemo-Autotrophic

Autotrophs which get their energy by oxidising the reduced energy found in inorganic compounds such as hydrogen sulfides

Decomposer

Feed on already dead plants and animals

Parasite

Feed on one or a very few host plants or animals while they are alive but do not usually kill their hosts, at least not immediately

Predator

Eat many prey organisms, typically killing them

Grazer

Consume parts of many prey organisms, but do not (usually) their prey, at least not immediately

Generalist

Animals that feed on a wide variety of foods

Specialist

Animals that may focus on particular parts of their prey but range over a number of species

Mutualistic

Relationship that is beneficial to both parties

Defenses

Any feature of an organism that increases the energy spent by a consumer in discovering or handling

Crypsis

Ability of an organism to conceal itself from a predator by having a colour, pattern, and shape that allows it to blend into the surrounding environment

Aposematism

Use of warning coloration to inform potential predators that an animal is poisonous, venomous, or otherwise dangerous

Mimics

One species resembles another that has easily recognizable characteristics and as a result deceives a potential predator

Global Conveyor Belt

Conveyor belt of ocean circulation is critical to redistributing heat across the Earth and mitigating human-driven global climate change

Biome

Characteristic regions with particular types of vegetation

Primary Production

Total amount of photosynthesis per area for a defined length of time

Epiphyte

Plants that grown on other plants

Specices Richness

Describes the number of species

Savanna

Characteristically consists of grassland with scattered small tress, but extrusive areas have no trees

Grassland/Praire

Natural vegetation over large areas in every continent except Antarctica

Desert

In most extreme form, too arid to bear any vegetation

Temperate Forest

Variety of types of vegetation

Succession

Process by which the mix of species and habitat in an area changes over time

Boreal Forest/Taiga

Coniferous and occur in regions where the short growing season and the polar cold of winter limit the vegetation and its associated fauna

Permafrost

Long-frozen soil below the surface

Tundra

North of the boreal forest, polar air masses and cold temperatures dominate even in summer

Watershed

Water entering a stream comes from its watershed; The land area where all the water draining from it comes to the steam through groundwater flows, surface runoff or both

Riparian

Species adapted to grow in the narrow strip along the stream where water is plentiful

Floodplain

Streams and rivers (at times of high discharge), flow onto the nearby land, termed the floodplain

Phytoplankton

Dominant primary producers in deep lakes

Zooplankton

Graze phytoplankton

Thermocline

Transitional zone below the surface layer where temperature rapidly declines

Swamp

Places where trees dominate the wetland

Marsh/Fen

Places where grasses and/or sedges dominate the wetland

Bog

Places where mosses of the genus Sphagnum dominate the wetland (usually very acidic)

Population

Functioning groups of individual organisms of the same species in a defined location

Modular/Module

Repeated production, usually rooted or fixed

Zygote

Eukaryotic cell formed by fertilization event between two gamates

Genet

Genetic individual that develops from the zygote and that produces ramets vegetatively

Annual

Species that complete a whole generation from seed to adult through to seeds again within a year

Perennial

Species that live for several or many years and may not reproduce in tier early years

Biennial

Plants that require two years to complete their life cycle

Iteroparous

Multiple reproductive cycles over the course of its lifetime

Semelparaous

Characterized by a single reproductive episode before death

Cohort

All individuals born within a particular period

Cohort Life Table

Table that records the survivorship of the members of the cohort overtime

Static Life Table

Describes the numbers of survivors of different ages

Age-Specific Fecundity Schedule

Fecundity of individuals also changes with their age, need to know how much individuals of different ages contribute to births in the population as a whole

Age Structure

Age classes in a population

Type I Survivorship Curve

Mortality is concentrated toward the end of the maximum life span

Type II Survivorship Curve

Straight line signifying a constant mortality rate from birth to maximum age, describes

Type III Survivorship Curve

Extensive early mortality, but high rate of subsequent survival

Dispersal

Describes the way individuals spread away from each other

Migration

Refers to the mass directional movement of large numbers of a species from one location to another

Inbreeding

Mating of close relatives in spieices that are normally outbreeding

Interspecific Competition

Individuals of one species suffer a reduction in fecundity, survivorship, or growth as a result of either exploitation of resources or interference by individuals from another species

Fundamental Niche

Combination of conditions and resources that allow that species to exist, grow, and reproduce when considered in isolation from any other species that might be harmful to its existence

Realized Niche

Combination of conditions and resources that allow it to exist, grow, and reproduce in the presence of specified other species that might be harmful to its existence

Niche Differentiation

Differentiation that allows competitors to coexist

Differential Resource Utilization

Species compete but coexist by utilizing slightly different resources in slightly different ways

Competitive Exclusion Principle

Two species can't coexist if they occupy exactly the same niche

Ghost of Competition Past

Coexisting species with an apparent potential to compete, will exhibit differences in behavior, physiology, or morphology that ensure that they compete little to not at all

Character Displacement

Morphological response to competition from another species

Ecological Release

Response to the absence of ecological effects of other species

Niche Complemntarity

Niche differentiation in a community of species involes several niche dimensions

Host

Prey consumed by parasites

Parasitoid

Flies and wasps whose larvae consume their insect larva host from within