What is Life?
description
Transcript of What is Life?
![Page 1: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/1.jpg)
1
What is Life?
– Living organisms:– are composed of cells– are complex and ordered– respond to their environment– can grow and reproduce– obtain and use energy– maintain internal balance– allow for evolutionary adaptation
![Page 2: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/2.jpg)
2
![Page 3: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/3.jpg)
3
Fig. 1.1
mitochondria
![Page 4: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/4.jpg)
4
Fig. 1.1(continued)
![Page 5: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/5.jpg)
5
The Nature of Science
Science aims to understand the natural world through observation and reasoning.
Science begins with observations, therefore, much of science is purely descriptive.
Science uses both deductive and inductive reasoning.
![Page 6: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/6.jpg)
6
The Nature of Science
Deductive reasoning uses general principles to make specific predictions.
Inductive reasoning uses specific observations to develop general conclusions.
![Page 7: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/7.jpg)
Theory(Hypotheses)
Experiments
Observations,Previous Research
HypothesesDeduction(general to specific)
Induction(specific to general)
The Scientific Way of Knowing:Inductive and Deductive approaches define the Scientific Method
Often, scientific investigations starts with Induction and moves to Deduction
![Page 8: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/8.jpg)
8
A scientific theory
- is a body of interconnected concepts
- is supported by a large fundament of evidence and scientific reasoning (usually the testing of numerous hypotheses)
- expresses ideas of which we are most certain
![Page 9: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/9.jpg)
9
![Page 10: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/10.jpg)
10
![Page 11: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/11.jpg)
11
Charles Darwin
evolution: modification of a species over generations
-“descent with modification”
natural selection: individuals with superior physical or behavioral characteristics are more likely to survive and reproduce than those without such characteristics
![Page 12: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/12.jpg)
12
One Piece of Darwin’s Induction
Similarity of related species
- Darwin noticed variations in related species living in different locations
![Page 13: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/13.jpg)
13
Another piece of Darwin’s Induction
Population growth vs. availability of resources
-population growth
is geometric
-increase in food
supply is arithmetic
![Page 14: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/14.jpg)
14
Evolutionary Deductive Evidence
Fossil record
- New fossils are found all the time
- Earth is older than previously believed
Mechanisms of heredity
- Early criticism of Darwin’s ideas were resolved by Mendel’s theories for genetic inheritance.
![Page 15: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/15.jpg)
15
• Mutations and their various combinations (hence new varieties) do not arise because they are needed -- they arise by chance.
• Mutations merely furnish random raw material for evolution, and rarely, if ever determine the course of the process.
• Natural selection is the differential reproduction of genotypes (genes). Cumulative selection is a powerfully constructive force, caught in action many times by evolutionary biologists.
• Evolution is, quite simply, the change in the genetic composition of a population over time.
An Evolution by Natural Selection Primer
![Page 16: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/16.jpg)
16
More Evolutionary Deductive Evidence
Comparative anatomy
- Homologous structures have same evolutionary origin, but different structure and function.
- Analogous structures have similar structure and function, but different evolutionary origin.
![Page 17: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/17.jpg)
Homologies of Religions and Languages
17
![Page 18: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/18.jpg)
18
Homologous Structures
![Page 19: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/19.jpg)
Homology vs. Analogy
19
![Page 20: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/20.jpg)
Homology vs. Analogy
20
Pterosaur
Bat
Bird
Figure from the National Center for Science Education
![Page 21: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/21.jpg)
21
More Evolutionary Deductive Evidence
Molecular Evidence
- Our increased understanding of DNA and protein structures has led to the development of more accurate phylogenetic trees.
![Page 22: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/22.jpg)
22
The Homeodomain, a protein structure found in a large family ofTranscription Factors, and responsible for binding DNA and regulating target genes
![Page 23: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/23.jpg)
23
Fig. 1.14
![Page 24: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/24.jpg)
The 3 Domains of Life on Earth
24
![Page 25: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/25.jpg)
Z-X Luo et al. Nature 476, 442-445 (2011) doi:10.1038/nature10291
Holotype specimen of Juramaia sinensis, Beijing Museum ofNatural History (BMNH) PM1343B.
![Page 26: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/26.jpg)
26
Unifying Themes in Biology
Cell theory
- All living organisms are made of cells, and all living cells come from preexisting cells.
Molecular basis of inheritance
- Genes, which control living organisms and are passed from one generation to the next, are found in DNA.
DeoxyriboNucleicAcid
![Page 27: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/27.jpg)
27
Unifying Themes in BiologyCells - information processing systems- Cells process information stored in DNA as well as information received
from the environment.
Emergent properties- New properties are present at one level of organization that are not
seen in the previous level.
Evolutionary change
- Living organisms have evolved from the same origin event. The diversity of life is the result of evolutionary change.
Evolutionary conservation
- Critical characteristics of early organisms are preserved and passed on to future generations.
![Page 28: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/28.jpg)
28
Unifying Themes in Biology
Structure and Function
-The function of a molecule is dependent on its structure.
-The structure of a molecule can often tell us about its function.
The DNA Polymerase IIIBeta Subunit (E. coli) with bound DNA
![Page 29: What is Life?](https://reader035.fdocuments.us/reader035/viewer/2022062807/56815167550346895dbf978b/html5/thumbnails/29.jpg)
29