Unit 10 Evolution

study ts

Herclitus

universe changes

Aristotle

Spontaneous generation - organisms come from non-living things.

Cuvier

Species dont change, extinction happens

Linnaeus

classified species based on fixed traits

Buffon

Species can change, but they don’t turn into other species.

Lamarck

Inheriance of acquired traits

Erasmus Darwin

All life comes from one ancestor

Hilaire

Monstrous births lead to new species

Chambers

The universe, and species, change

Biological fitness

ability to survive and reproduce

Adaptation

trait that is benficial in a given/specific environment

Four Principles

Variation: differences exist in a population because of mutations and sexual reproduction

Overproduction: not every individual can survive, creating competition

Adaptation: organisms w/ beneficial traits will survive and reproduce

Descent w/ mod: In an unchanging environment, there will be mroe individuals with beneficial traits in each generation

Selective pressures make some traits _____ and some traits ___

beneficial and deletarious

Selective pressure examples

Competition, Predation, CLimate, Disease, and Humans

Example of selective pressures

Documented drought effects in 1977 and 2003.

1977: Plants w/ small seeds die, leaving only large seeds for birds, and birds with big beaks live

2003: Plants w/ big seeds die, leaving only small seeds for birds, and birds with small beaks live.

Darwin’s influences

Gradualism: Earth changes over time

Uniformitarianism: processes that change Earth over time are uniform throughout time

Populations are limited by resource availability

Voyage of HMS Beagle: Darwin observed variation in species (finches) and he saw adaptations to their environment (also finches)

Theory of Natural Selection

1. Mechanism by which evolution occurs

2. Individuals who have inherited beneficial traits will produce more offspring than others

3. Bio fitness (mentioned on other slide)

4. Adaptation (other slide)

5. Four Principles (other slide)

Fossils

1. Preserved remains of living things

2. Species change over time

3. T. rex

Biogeography

Geographical distribution of organisms

Species change over time

Darwin’s finches (island based)

Embryology

Study of embryos and development

similarities indicate common ancestor

Fish and human

Homologous Structures

Different functions, same structure

Similarities indicate a common ancestor

Horse vs Human legs

Analogous Structures

Different structures, same function

Difference in structure indicates a DISTANT common ancestor

Bat wing and Butterfly wing

Vestigial Structure

Body part with lbarely any function

Species change over time

Tailbone (human)

DNA comparison

Compare sequences of DNA from different species

Similarities indicate a common ancestor

Humans vs Chimps (98% shared DNA sequence)

Protein Comparison

Comparing amino acid sequences of different species

Similarities indicate a common ancestor

Human and Gorilla

Allele Frequency

Percentages of alleles in a population

Gene Flow

Movement of alleles from one pop to another

Genetic Drift

Change in allele frequency in a small population

Bottleneck effect

Event that drastically reduces the pop, causing genetic drift

Founder Effect

A small group colonizes a new area, causing genetic drift

Intersexual Selection

One sex of species chooses characteristics, challenging allele frequencies (ornaments = Inter)

Intrasexual Selection

One sex competes for mates, choosing better competitions

Artifical Selection

Humans select for certain traits of a species, changing allele frequencies

Species

group of organisms that can produce viable, fertile offspring (babies that can make babies)

Speciation

one species splitting into two

Conditions Necessary for this: Natural Selection and Isolation

Types of isolation

Mechanical: members of different pops can’t have viable babies

Behavioral: Different pops adapt different mating behaviors

Geographic: pops separated by physical barrier

Temporal: pops have different mating seasons

Read the Cladogram and answer:

How are Chimps and Bears related?

Which animals have common tetrapod ancestors?

What is the youngest animal present?

Common mammal ancestor

Newt, Lizard, Bear, and Chimp

Chimp

Read the Cladogram and answer for the RIGHT SIDE ONLY:

Which are the most related

Which one is the youngest

Is C related to B

A and B

Trick Question: they’re all the same age (im rly funny)

Yes, through the node on the bottom

Good luck - this is the end of the slides unless u decided to click shuffle, so keep going if u shuffled the cards.

Final stretch, last test; get a good grade so u don’t take the final. U got it. I believe.