Evolution 4.4- Speciation Flashcards
1.1- Allopatric Speciation, 1.2- Divergent Evolution, Convergent Evolution, and Adaptive Radiation
What is speciation?
Speciation is the process by which two parts of a population become reproductively isolated, eventually forming two new species.
How does speciation result from genetic changes?
Genetic changes accumulate due to different selection pressures or genetic drift in geographically isolated populations, leading to the formation of new species.
What is allopatric speciation?
Allopatric speciation occurs when two sub-populations are physically isolated by a geographical barrier, evolving under different selective pressures until they become separate species.
What is sympatric speciation?
Sympatric speciation occurs when two sub-populations in the same geographic area become reproductively isolated due to mutations or chromosomal abnormalities, preventing some members from breeding with the rest.
What are the steps in allopatric speciation?
1) Physical isolation of gene pools
2) exposure to different selective pressures
3) accumulation of genetic differences until the populations can no longer interbreed to produce fertile offspring.
What is a homologous structure in divergent evolution?
A homologous structure is a similar anatomical feature found in species with a common ancestor but has evolved to serve different functions.
What is adaptive radiation?
Adaptive radiation is a special case of divergent evolution where a single species rapidly diverges into multiple species, each adapting to different ecological niches.
What is divergent evolution?
Divergent evolution occurs when species with a common ancestor evolve and accumulate differences over time due to different selective pressures, eventually forming new species.
What are analogous structures in convergent evolution?
Analogous structures have different origins but similar functions, as the species are not related but have evolved similar features due to similar selective pressures.
What is convergent evolution?
Convergent evolution occurs when distantly related species evolve similar characteristics due to similar environmental pressures, despite having no common ancestor.
