8.L.4.1 Evolution & Genetics
Presentation
•
Science
•
8th Grade
•
Medium
+4
Standards-aligned
Krystal Kovach
Used 8+ times
FREE Resource
26 Slides • 15 Questions
1
8.L.4 Evolution & Genetics
Focus Standard 8.L.4.1
2
Theory of Evolution
What evidence do scientists have to prove the theory of evolution?
3
4
5
Evolution
Since genes control traits and we know that traits can be inherited. What determines which traits are seen most often in a population of organisms?
Did you know that the male red deer needs big antlers in order to attract a mate? The male deers with big antlers are more desirable to females so they are chosen more often.
This process is known as evolution.
6
Multiple Choice
7
8
Evolution
Applies to a population, a group of the same species that live in area, rather than just an individual organism. The whole group!
Species is group of organims that can mate and produce offspring that can mate.
Evolutionary changes happen at the genetic level. Organism genes change in different ways during reproduction which create new and improved traits.
Occurs over many, many generations.
9
Multiple Choice
10
Multiple Choice
11
Multiple Choice
12
13
Similar Species
Charles Darwin was the father of the Theory of Evolution.
He took a voyage to several islands when he was around 20 years old. On his voyage he visited the Galapagos Islands. They are located off the current coast of Ecuador. where he discovered a species of birds...Finches.
He noticed that the Finches on each of the Islands were different from each other and different from those on the mainland.
14
Finches on Galapagos Islands
Because Darwin drew each of these by hand and in grave detail he noticed that each of the Finches beaks were very different.
Some birds had strong wide beaks, while others had narrow needle like beaks.
He determined that the shape of the beak determines what kind of food they could eat.
We will see this in the next slide.
15
Finches Continued
The finches with the strong wide beaks eat seeds because their beaks were perfect for cracking open the seeds.
The birds with the narrow needle like beaks eat insects because their beaks were perfect for getting into places where insects lived.
So since each Finch reproduced in isolation from each other in Theory. Different traits evolved that were suited for the conditions of a specific island. Thus this is why Finches on different islands had different beaks.
16
Multiple Choice
17
Open Ended
18
EVIDENCE #2-Fossils
Most of the evidence of Evolution was originally found as fossils.
Fossils can preserve the structures of an organism in many ways. They give us a good idea of what certain organisms looked like throughout Earth's long history. The fossil record is not complete.
Examples include: Bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, petrified wood, oil, coal, and DNA remnants.
19
Open Ended
20
Evidence #3-SImilar DNA
Scientists compare the DNA of different species in order to find similarities.
DNA similarities can tell us about common ancestry.
DNA analysis has allowed us to understand evolution better and forced us to reclassify species as more or less related than we originally thought.
Our DNA is very similar of that in Chimpanzees but WE DID NOT COME FROM MONKEYS.
21
Evidence #4-Structural Clues (Comparative Anatomy)
Embryonic Similarities
Homologous & Analagous Structures
Vestigial Structures
22
Ebmryonic Similarities
Embryology is the study of embryos. Comparing the development of multiple species embryos helps us understand that many species share characteristics in their early development.
Example: all of these have musles arranged in groups or bundles and a tail. They also have a hard protective covering over the brain.
23
Homologous Structures
Many species living today have similar body structures.
Examples of Homologous Structures: Human arms, bird wings, whale flippers, dog forearms, and frog forelimbs.
These structures support the idea that the different animals descend from a common ancestor and serve as evidence of evolution.
24
Analogous Structures
Analogous structures are similar structures that evolved independently in two living organisms to serve the same purpose.
The term “analogous structures” comes from the root word “analogy,” which is a device in the English language where two different things are based on their similarities.
The structures are not the same, and were not inherited from the same ancestor. But they look similar and serve a similar purpose.
25
Vestigial Structures
Vestigial structures are evolutionary leftovers.
They are structures that have no function in an organism, but they come from a common ancestor that did need that structure. Over time, evolution and adaptation eliminated the need for these structures, yet they remain.
Humans have many examples of vestigial structures in their bodies. The tailbone is one body part that does not serve a function anymore. It starts as a tail and then the vertebrae fuses into tailbone.
26
Multiple Select
27
28
Multiple Select
29
30
Open Ended
Put the steps of evolution by natural selection in order. You just need to type the number in order.
31
32
Multiple Select
33
34
35
36
Open Ended
37
38
Open Ended
39
40
Multiple Choice
41
Open Ended
8.L.4 Evolution & Genetics
Focus Standard 8.L.4.1
Show answer
Auto Play
Slide 1 / 41
SLIDE
