Chapter 14 BioDiversity

Carl von Linne’s system of classification

Didn’t show proper evolutionary relationships and the levels have no meaning, they’re based on arbitrary criteria.

Morphological Species Concept

Based on anatomical similarities and differences

Which Concept is good for determining differences in fossils?

The Morphological Species Concept

Which Concept is good for plants and bacteria?

The Ecological Species Concept

Biological Species Concept

If 2 organisms can produce viable, fertile offspring, they are the same species.

Ecological Species Concept

Two organisms that have the same habitat / niche requirements are the same species.

Phylogenetic Species Concept

Based on similarities and differences within the gene sequence.

Reproductive Isolation

A segment of the population is separated from the main population, so the two segments no longer mate.

Genetic Divergence

Two populations experience different microevolutionary events causing the 2 gene pools to become more and more different over time.

What happens after Genetic Divergence or Reproductive Isolation?

The two populations can be reintroduced, but they no longer see each other as mates. This is the point that you can call them a different species.

Adaptive Radiation

A period of rapid diversification

How does Adaptive Radiation work after mass extinction?

During the rapid diversification, the survivors move into the vacant niches.

Prezygotic Barries

Prevent fertilization from occurring.

Mechanical Isolation

Reproductive parts don’t work together anymore.

Temporal Isolation

Different breading seasons.

Behavioral Isolation

Different courtship ritual (ways of attracting mates)

Ecological Isolation

Different habitat or niche

Gamete Mortality

One or both gametes can’t survive for long enough for fertilization.

Postzygotic Barriers

Produce viable offspring but either sterile or end up sick.

Reduced Hybrid Fertility

Offspring are viable but they are sterile, not fertile.

Hybrid breakdown

Offspring are viable and fertile, but the second generation is sick, weak, and dies.

Pros of the biological species concept?

Good for classifying animals because they’re limited in their ability to hybridize (cross-breed)

Cons of the biological species concept?

Bad for other organisms which have greater ability to hybridize (cross-breed)
*artificially loses biodiversity

Allopatric Speciation

A geographic feature separates a population into two different segments.

Sympatric Speciation

Evolution of a new species from a single ancestral species without any geological influence.