Knowt 5 - Classification and Macroevolution

The Science of Taxonomy and Speciation

Microevolution

Allele frequency; small scale; populations

Macroevolution (2 Ideas)

1. Significant changes accumulated over a long period of time

2. Includes speciation requires some form of separation/isolation

Systematics (2 Ideas)

1. The field of science concerned with studying the diversity of all life on earth, past and present

2. Concerned with taxonomy and phylogeny

Taxonomy (2 Ideas)

1. The science of naming and classifying organisms.

2. Standardized and universal.

Phylogeny (3 Ideas)

1. The study of evolutionary relationships between taxa (si. taxon)

2. Based on hypotheses and inference

3. Represented in phylograms

Classification (1. Top → 8. Bottom)

1. Domain

2. Kingdom

3. Phylum

4. Class

5. Order

6. Family

7. Genus

8. Species

Domain

Eucarya

Kingdom

Animalia

Phylum

Chordates

Class

Mammalia

Order

Primates

Family

Hominidae

Genus

Homo

Species

Homo Sapiens

Basic Principles - Homologous Traits (4 Ideas)

1. A trait that is similar between organisms because they share a common ancestor

2. Can serve same or different function

3. Divergent evolution

4. Example: tetrapods

   • Tiktaalik

Homologous Traits - 2 Types

1. Ancestral Traits

2. Derived Traits

Ancestral Traits

Traits from a distant ancestor that are shared among multiple lineages; older

Derived Traits

A trait that is a modification of an ancestral form; can be shared or unique; newer.

Basic Principles - Analogous Characters (3 Ideas)

1. Characters that are similar between species that share a common function but were developed independently

2. Convergent evolution

3. Example: cetaceans, sirenians, pinnipeds

Biological Species Concept

1. Species a la John Ray (1627-1705)

2. Individuals who can breed together and produce fertile offspring

Paleospecies

1. Extinct species identified in fossil remains

2. Crucial to identify source of variation

   • Intraspecific?

   • Interspecific?

Geological Time Scale (2 Ideas)

1. Ordering of deep time into eons, eras, epochs, periods, and stages

2. 4.5 Ga – present

Adaptive Radiation (3 Ideas)

1. Species rapidly expand into new ecological niches, diversify, and diverge

2. Followed by diversification and speciation

3. New niches exert new selective pressures

Adaptive Radiation - 3 Examples

1. Reptiles in Mesozoic

2. Mammals in Cenozoic

3. Darwin's finches

Generalized traits

1. Traits adapted to serve many functions

2. Good for adapting to new econiches

Specialized traits

1. Trait adapted for specific function

2. Restricted to original econiche

Basic Principles - Clade (3 Ideas)

1. All descendants of a single common ancestor

2. I.e., clades are monophyletic

3. Basis of cladistics