Chapter 24 The Origin of Species (Elac)

speciation

Fill in the blank

______ is the origin of new species

Speciation

What is microevolution?

Microevolution consists of adaptations that evolve within a population

What is macroevolution?

Macroevolution refers to large-scale evolutionary changes that occur over long periods of time, leading to the emergence of new species and major taxonomic groups.

What is the biological concept?

The biological concept states a group of populations whose members have the potential to interbreed in nature and produce viable offspring, fertile offspring that can reproduce. They do not breed successfully with other populations

Biological species concept ex 1

biological species concept ex 2

What is reproductive isolation?

is the existence of barrier that prevent species from mating with others, which can lead to speciation. It can occur through various barriers, including temporal, behavioral, mechanical, habitat, and gametic isolation.

Define hybrids

Hybrids are offspring of crosses between different species

Fill in the blank

Reproductive isolation can be classified by whether factors occurred before or after ______

fertilization

What are prezygotic barriers?

barriers that occur before fertilization, preventing mating or fertilization between different species.

List all the prezygotic barriers

including temporal isolation, habitat isolation, behavioral isolation, mechanical isolation, and gametic isolation.

What is habitat isolation?

Habitat isolation occurs when two species live in different habitats and therefore do not meet and mate, because they live in different habitats, even though not isolated by physical barriers .

What is temporal isolation?

Temporal isolation occurs when two species breed at different times of the day, season, or year, preventing them from mating.

What is mechanical isolation?

Mechanical isolation occurs when two species are physically unable to mate due to differences in their reproductive structures.

What is gametic isolation?

Gametic isolation occurs when two species' gametes (sperm and eggs) are incompatible, preventing fertilization even if they meet.

What is behavioral isolation?

Behavioral isolation occurs when two species have different mating behaviors or rituals, leading to a failure to recognize each other as potential mates.

What are post zygotic barriers?

barriers preventing the hybrid zygote from developing into a viable, fertile adult.

Fill in the blank

This phrase ____ hybrid _____ describes hybrids reduced fitness, meaning that the offspring is weak

reduced; viability

Fill in the blank

This phrase ____ hybrid ____ describes hybrids fertility, means sterile offspring

reduced hybrid fertility

What is hybrid breakdown?

A phenomenon where the first-generation hybrids are viable and fertile, but when they mate, their offspring are inviable or sterile.

Which organisms do the biological species concept not apply for?

Organisms that reproduce asexually and fossils

What is the morphological species concept?

defines a species by its structural features

Fill in the blank

The ______ species concept views a species in terms of niche

ecological

what is a niche?

The role or function of an organism within its environment, including its habitat, resource use, and interactions with other organisms.

What is the phylogenetic species concept?

defines a species as the smallest phyletic group on a phylogenetic tree, sharing a common ancestor.

True or False

Speciation can take place with or without geography seperation

True

what are the 2 ways speciation can occur?

Allopatric and sympatric speciation.

What is allopatric speciation?

A form of speciation that occurs when populations are geographically separated, leading to reproductive isolation and divergence over time.

What is sympatric speciation?

A form of speciation that occurs without geographic separation, where populations develop reproductive barriers while living in the same area.

List the reasons sympatric speciation occurs

Polyploidy, and sexual attraction/preferences

What is polypoidy?

The presence of extra sets of chromosomes due to accidents during cell division

What is autoploidy?

Is a species with more than 2 chromosome set derived from the one species

What is allopoidy?

A species with multiple set of chromosomes derived from different species

In what kind of kingdom is polypoidy common?

Plants, they can't move so they intentionally do this to diversify

Can niches from the ecological species concept lead to sympatric speciation?

Yes

True or false

Sexual selection can drive sympatric speciation

True

What is a hybrid zone?

A z I ne in which different species mate and produce hybrids

Fill in the blank

A hybrid zone can occur in a ______ where adjacent species meet

Band

True or false

Hybrids usually have increased fitness in comparison to their parent

False

What are the 3 possibilities that can occur in a hybrid zone?

Reinforcement, fusion, and stabilizing

What is fusion (hybrid zones)?

The hybrid starts mating with it's parent species and they eventually just go away

What is stabilizing (hybrid zones)?

The hybrids are thriving they are doing well

Read

Brad patterns in speciation can be studied using a fossil record, morphological data, or molecular data

What is punctuated equilibrium?

Describe periods of stasis or no change punctuated by brief change

What is gradualism?

Darwin's model of cmevolution being slow, continous, and gradual

What 2 models of evololution contradict themselves?

The punctuated equilibrium and the gradualism model

What is hybrid breakdown?

The first generation of hybrids are fertile and viable and the next generation are less fertile or sterile

What is reinforcement?

an evolutionary process where natural selection strengthens prezygotic reproductive barriers between populations, preventing the production of unfit hybrid offspring. Reinforces the parents