bio review unit 2

bottle neck effect

a large reduction in population size leading to a decrease in genetic diversity

Peripatric speciation

when a new niche i entered by a population and then they are isolated from the rest of the pop

parapatric speciation

when a population enteres a new niche without being isolated from the rest of the species

allopatric speciation

when a physical barrier comes between a population and isolates them from each other

sympatric

when a population becomes reproductively isolated without any physical isolations withing the habitat.

mechanical isolation

physical differences in reproductive organs prevent mating between two species

gametic isolation

when the gametes (egg and sperm) can come into contact but they are incompatible and will not fertilize/make a zygote.

zygote mortality

the death of a zygote before it can develop into an embryo or offspring

hybrid inviability

when the offspring has a reduced chance of become reproductivly mature or viable

hybrid breakdown

a reproductive failure in F2 or later generations - since F1 was viable and fertile

adaptive radiation

an evolutionary process that produces new species from a single, rapidly diversifying lineage

importance of mass extinctions

lead to the diversification of surviving lineages, allowing them to occupy vacant ecological niches and evolve new adaptations

divergent evolution

when an ancestral species evolves into two or more new species

convergent evolution

when unrealted species form similar traits from adapting to similar environments

selective pressure

environmental traits that favor certain traits in a population

selective advantage

a trait that is favored by their environment and helps a species survives

evidence of natural selection

fossils, anatomy (homologous, analougous, vestigal), embryonology

what can you learn from fossils and how its formed briefly

evidence for evolution (anotomy), how old a species is/ what era their from, how they lived, where they lived and their environmental conditions (ex sea water or fresh water?)

vestigial structures

anatomical structures or traits that were once functional in an organism's ancestors but have since lost their original function, often becoming reduced or non-functional

embryology

we share many similar developmental phases while in utero

survival of the fittest/descent within modification

• more offspring born than can survive

• ressources are limited

• variation between individuals

• some will be better suited to the environment and have offspring while some won’t