Speciation and Macroevolution

do organisms change genetically throughout their lifetime

no

do populations change genetically over time

yes

what is the process of speciation

the splitting of one species into two distinct species

species is a ____ classification but can be defined in ____ ways

taxonomic, several

what is the definition of a species

a group of organism that can reproduce and create offspring that can also reproduce (but we can define ‘species’ in other ways)

what are the 4 concepts that cam be used to define a species

morphological species concept, evolutionary species concept, phylogenetic species concept, biological species concept

what is morphology

study of an organism’s form, anatomy, and relationship between their structures

Morphological species concept: organisms are defined by their distinct physical characteristics known as

diagnostic traits

what are cryptic species

two different species that look identical but differ in some other ways (courtship, ect.)

_____ species concept if tough to use on some organism like bacteria, but helpful in paleontology

morphological

bacteria have the most diversity but they look very

similar

evolutionary species concept relies on the identification of certain morphological traits in the

fossil record

evolutionary species concept tracks evolution as _____ change over time

specific characteristics

what is a phylogeny

a family tree

phylogenetic species concept is used to identify species based on

common ancestor

a branch that contains all the descendants of a common ancestor is said to be

monophyletic

phylogenetic species are based on ____ not morphology

DNA code

what does viable mean in terms of a living thing

alive/can live

biological species concept relies on ___ to identify species

reproductive isolation

an embryo that is not viable means that the embryo is not

alive

biological species concept can’t be applied to _____ organisms or ____

asexually reproducing organisms or fossils

which species concept is difficult to test in nature

biological species concept

for two species to remain separate, populations must be _____

reproductively isolated

for two species to remain separate, populations must be reproductively isolated. ____ must not occur between them.

gene flow

barriers that prevent successful reproduction are called

isolated mechanisms

what are the two main groups of reproductive isolation mechanism

prezygotic and postzygotic isolation

what is a zygote

a fertilized egg (sperm + egg = zygote)

reproductively isolate means there is no ___ between the populations

gene flow

prezygotic=

premating, mating

postzygotic=

post fertilization

what are the three types of premating reproductive isolation

habitat isolation, temporal isolation, behavioral isolation

(reproductive isolation)what is habitat isolation

at same locale occupy different habitats. (if can’t get together there is no zygote)

(reproductive isolation)what is temporal isolation

species reproduce at different seasons or different times of day

(reproductive isolation)what is behaviroal isolation

in animal species, courtship behaviors differs, or individuals respond to different songs, calls, pheromones, or other signals

what are the two types of mating reproductive isolation

mechanical isolation and gametic isolation

(reproductive isolation) what is mechanical isolation

Genitalia between species are unsuitable for one another. (Anatomy does not fit together)

(reproductive isolation) what is gametic isolation

sperm cannot reach or fertilize egg

what are the three types of postzygotic isolation mechanisms

zygotic mortality, hybrid sterility, F2 fitness

(reproductive isolation) zygote mortality

fertilization occurs but zygote does not service

(reproductive isolation) hybrid sterility

hybrid services but sterile and cannot reproduce

(reproductive isolation) F2 fitness

hybrid is fertile but F2 hybrid has reduced fitness (hybrid can reproduce but the offspring of the hybrid cannot)

speciation

the splitting 1 species → 2 species

what are the main modes of speciation

allopatric and sympatric

which type of speciation has a geographic barrier

allopatric

does sympatric speciation have a geographic barrier

no

what does ploidy =

number of chromosomes

what are the two theory of speciation

gradualism and punctuated equlibrium

gradualism sepciation =

slowly over time change occur gradually

punctuated equilibrium speciation=

periods of rapid change followed by periods of no change, these rapid change, these rapid changes often times occur after a big event

evolution can be divided into ___ different categories

2 (divergent evolution and convergent evolution)

what are the 2 different categories of evolution

divergent and convergent

what type of evolution of organisms do not share a common ancestor but become more similar

convergent

what type of evolution do organisms have a common ancestor but become less similar

divergent evolution

homologous traits and common ancestors evolution is ___ evolution

divergent

what type of evolution occurs when a single ancestral species gives rise to a variety of new species as each adapts to a specific

divergent evolution

what type of evolution occurs in times of ecological release

divergent evolution

ecological release

competition is reduced, and individuals are allowed to explore diff resources

divergent evolution occurs following

extinction events, migration to new area, following ice ages

what type of evolution is analogous traits, and similar traits due to similar lifestyle of habitat

convergent evolution

what do HOX genes do

specific regions of the body plan of a embryo, ensure that the correct structures in the correct planes

what type of genes are HOX genes

homeobox genes