Biology Q2 Test Terms

Biological fitness

An individual’s ability to survive and successfully reproduce

Adaptive traits

Traits that improve survival and reproduction in a particular environment

Adaptation

An advantageous trait or the evolutionary process that produces adaptive traits

Generation time

A factor affecting how quickly a species can adapt

Species

Members of a group that can mate and produce fertile offspring

Biological species concept

Defines a species by its ability to interbreed and produce fertile offspring

Reproductive isolation

When populations are prevented from reproducing with each other

Morphology

The physical characteristics of organisms

Genetic divergence

The accumulation of DNA sequence differences between populations over time

Speciation

-The formation of two or more species from one original species

-Allopatric Speciation - geographical isolation

-Sympatric Speciation - same location/ develops into different species by changing chromosome number

Gene flow

The passing of alleles between populations

Geographic isolation

Physical separation between populations

Allopatric speciation

Formation of new species from geographically isolated populations

Sympatric speciation

Formation of new species without geographic isolation

Ecological isolation

Reproductive isolation caused by differences in habitat, breeding season, or breeding time

Coevolution

Two species evolving in response to each other

Convergent evolution

Different species becoming more alike because they adapt to similar environments

Reproductive barrier

A barrier that prevents two species from reproducing

Prezygotic barrier

A barrier that prevents fertilization and zygote formation

Postzygotic barrier

A barrier that prevents zygotes from developing into fertile offspring

Gamete incompatibility

Egg and sperm cannot fuse for genetic reasons

Mechanical isolation

Physical incompatibility prevents mating

Behavioral isolation

Differences in mating behavior prevent reproduction

Hybrid sterility

Hybrid offspring cannot reproduce

Polyploidy

Having extra full sets of chromosomes

Viable

Able to survive

Fertile

Able to reproduce

Cladogram

Shows the different features and traits (doesn’t show time and how closely related the animals are)

Phylogenetic tree

Shows the time and relativeness of the organisms

Divergent evolution

Homologous structure (same structure)/ common ancestry/ adaptive radiation

Convergent evolution

Analogus structure (same function)/ no common ancestor

Co evolution

2 different species evolve together

Derived Character

New feature in cladogram in each branch point

Prezygotic barrier

ecological isolation, geographic isolation, reproductive isolation, behavioral isolation, temporal isolation ( prevent fertilized eggs from forming)

Postzygotic Barrier

Fertilized eggs are formed, but the organism will naturally abort it (zygote death), hybrid sterility, & 2nd generation cannot reproduce

Vistigial Structure

Feature that was used in ancestor but not currently

Tempo of evolution

Gradualism - accumulate small changes over time

Punctuated equilibrium - for a long time no change, but for short time many big changes