Evolution

Only traits that are beneficial to the survival & reproduction of a population are naturally selected for. There is no #traitgoals for evolution.

• Traits that have no impact on reproduction are neither selected for or against.
• Example: The trait of having feathers probably did not evolve for flight.

Evolution is neither completely random or non-random.

• Random mutations
• Non-random environmental selection

Being the fittest does NOT mean being the strongest.

Chimpanzee are the organism that Homo sapians are most closely related. The two species would have a common ancestor that was neither a chimp or human.

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Evolution

History of Evolution

Lamarck vs. Darwin

Types of Selection

Offspring born with longer neck

Cannot reach taller branches

SEXUAL SELECTION

Traits become more or less common depending on an individual's ability to mate with more or better partners.

Describe the relationship between the amount of biodiversity and the ability of a population to adapt to a changing environment.

Explain the relationships of animal adaptations to their environment.

Reaches more food than short necks

NATURAL SELECTION

Stretches out neck

Traits become more or less common depending on an individual's ability to survive and reproduce.

Reproduces more than short necks

Offspring born with longer neck

4 Postulates of Natural Selection

Individuals within populations are variable.

Long necks more common in population

Variations among individuals are, at least in part, passed from parents to offspring.

In every generation, some individuals are more successful at surviving and reproducing than others.

Research Project

The survival and reproduction of individuals are not random; instead they are tied to the variation among individuals. The individuals with the most favorable variations are naturally selected.

ARTIFICIAL SELECTION

Traits are selected for by humans, not nature.

History of the Theory of Evolution

Classification System:

• Showed similarities of different organisms.
• Classified humans as having similarities with other animals.

PRESSURES: What can cause selection.

Geology:

• Older rock layers were found beneath younger rock layers, thus can compare ages of fossils by where they are found.
• Uniformitarianism: geologic processes in the past continue to work in the same ways in the present.

• Table 1 = Linnaeus
• Table 2 = Hutton
• Table 3 = Lamarck
• Table 4 = Malthus
• Table 5 = Cuvier
• Table 6 = Darwin
• Table 7 = Mendel
• Table 8 = Wallace

• Overpopulation
• Changing Environments
• Resource Competition
• Predators

Instructions

Speciation

Your table will conduct research on the assigned scientist and provide information concerning the following topics.

WHAT IS A SPECIES?

A group of individual organisms that are capable of interbreeding to produce fertile offspring in nature.

EXAMPLE OF SPECIATION

1. Life span years.

2. One interesting fact about scientist's life.

3. Summary of scientific work.

4. Biggest contribution(s) to the development of evolution.

5. Year(s) in which biggest contribution(s) was/were made.

DIVERGENT EVOLUTION

Two or more related species becoming more and more dissimilar.

PATTERNS OF EVOLUTION

CONVERGENT EVOLUTION

Different organisms that live in similar habitats become more alike in appearance and behavior.

CO-EVOLUTION/PARALLEL EVOLUTION

Fish

The evolution of one species is associated with the evolution of another species.

Mammal

Reptile

Evolution & natural selection are not the same thing.

• Natural selection is one mechanism through which evolution occurs.

Only traits that are beneficial to the survival & reproduction of a population are naturally selected for. There is no #traitgoals for evolution.

• Traits that have no impact on reproduction are neither selected for or against.
• Example: The trait of having feathers probably did not evolve for flight.

Fossil Record

Common Misconceptions

Evolution is neither completely random or non-random.

• Random mutations
• Non-random environmental selection

Fossil: remains or traces of an organism that died long ago.

Fossil Record

Correcting Common Misconceptions

Fossil: remains or traces of an organism that died long ago.

Individual organisms do not evolve.

• Populations evolve through changes in allele frequency.

Comparative Anatomy

Being the fittest does NOT mean being the strongest.

Individual organisms do not evolve.

• Populations evolve through changes in allele frequency.

Transitional Species: have features that are intermediate between those of hypothesized ancestors and later descendant species.

Homologous structures: anatomically similar structures that occur in different species.

Chimpanzee are the organism that Homo sapians are most closely related. The two species would have a common ancestor that was neither a chimp or human.

Comparative Anatomy

Analogous structures: have closely related functions but do not derive from the same ancestral structure.

Transitional Species: have features that are intermediate between those of hypothesized ancestors and later descendant species.

Evolution is still happening.

Homologous structures: anatomically similar structures that occur in different species.

Analogous structures: have closely related functions but do not derive from the same ancestral structure.

Evolution is still happening.

Do the strongest really survive?

Darwinian Fitness: ability of an individual to survive and reproduce in its environment.

Do the strongest really survive?

Darwinian Fitness: ability of an individual to survive and reproduce in its environment.

What is biological evolution?

Comparative Anatomy

What is biological evolution?

Evidence of Evolution

Comparative Anatomy

Calf

Chick

Fish

Hog

Human

Rabbit

Salamander

Tortoise

Embryological Evidence: Organisms share common structures during early development.

Evidence of Evolution

Biological Molecules

Vestigial Structures: A structure in an organism that has lost all or most of its original function in the course of evolution

Apply evidence from the fossil record, comparative anatomy, amino acid sequences and DNA structure that support modern classification systems.

The Theory of Evolution

Scientific Theory: well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed through observation and experimentation.

The more similarities within the DNA and Amino Acid sequences = more closely related.

Biological Molecules

Apply evidence from the fossil record, comparative anatomy, amino acid sequences and DNA structure that support modern classification systems.

The Theory of Evolution

Scientific Theory: well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed through observation and experimentation.

The more similarities within the DNA and Amino Acid sequences = more closely related.

Biological Evolution: any change in the frequency of alleles within a gene pool from one generation to the next.

Artificial Selection: traits are not selected by nature. Desired traits are selected for by humans.

Artificial Selection

Evolution in Action

Convergent: evolution towards similar traits in unrelated species.

Divergent: evolution towards different traits in closely related species.

Divergent vs. Convergent Evolution

Biological Species Concept: a species is a single kind of organism that are morphologically similar and can interbreed to produce fully fertile offspring.

Speciation

American goatsbeard (wild flowers)

Have we ever seen speciation?

Review Videos!

Evidence

Speciation

Hardy-Weinberg

History

Natural Selection