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BIO DEATH #3 > Speciation > Flashcards

Flashcards in Speciation Deck (14)
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1

Speciation

-origin of new species
-results in two of more descendant species

2

biological species

group of populations which can interbreed but are reproductively isolated from other such groups

3

isolating mechanisms

pre-zygotic barriers
post-zygotic barriers

4

Pre- zygotic barriers

-barriers to successful mating and fertilization
-habitat, temporal, behavioral, mechanical, gametic

5

Post- zygotic barriers

-fertilization occurs but hybrids are inviable or infertile or -breakdown after only a few generations
-one reciprocal cross is fertile, but the other isn't

6

allopatric speciation

-interruptions of gene flow are due to geographical separation.

7

sympatric speciation

some interruptions of gene flow occur without geographical separation
-increase in # of chromosomes

8

autopolyploidy

meiotic error where they produce gametes with all (unreduced) chromosomes
-become isolated from parent species

9

allopolyploidy

mess up chromosomal segregation at meiosis
-most common

10

convergent evolution

traits in two or more organisms appear to be similar, but they evolved independently in each lineage

11

homology

same or similar relation. common ancestry

12

homoplasy

characteristic shred by a set of species but not present in a common ancestor

13

anisogamy

post zygotic care often much higher among females

14

vicariant speciation

speciation due to geographical disturbances