Question

How do we distinguish the terms hypothesis. theory, paradigm, and scientific fact? What are Darwin's five theories of evolution (as identified by Ernst Mayr)? Which are accepted as fact and which continue to stir controversy among biologists? What major obstacle confronted Darwin's theory of natural proposed? How was this obstacle overcome? Describe the respective contributions of the genetic approach and cell biology to formulating the chromosomal theory of

Answer 1

7. How do we distinguish the terms hypothesis, theory, paradigm and scientific fact?

A hypothesis is a testable idea; it is subject to experimental observation to help determine its validity.

A theory is a well-established scientific principle that is supported by convincing experimental and observational evidence.

A paradigm is a central conceptual framework for how you can view the world around you. A paradigm can be so pervasive and broadly accepted as to be almost unnoticed, much the way you don't usually notice the air you breathe

Scientific Fact-It is important to realize that our understanding of science can questioned at all levels. However, theories and paradigms that have continued to be useful in predicting experiments and understanding the natural world are considered scientific fact

8. What are darwin’s five theories of evolution as identified by Ernst Mayr? Which are accepted as fact and which continue to stir controversy among biologists?

a. Perpetual Change: The living world is constantly changing.

b. Common Descent: all forms of life descend from a common ancestor

c. Multiplication of Species: New species evolve by splitting and transforming older ones.   

d. Gradualism: large differences among organisms are due to the accumulation of small differences over time.

e. Natural Selection: Variation exists, variation is inheritable, Some individuals leave more offspring than others.

9. What are major obstacles confronted Darwin’s theory of natural selection even it was first propose? How was this obstacle overcome?

Darwin’s Theory of natural selection did not have a clear mechanism of heredity. Mendel’s genetic experiment confirmed genetic inheritance with the chromosomal theory of inheritance

10. Describe the respective contributions of the genetic approach and cell biology to formulating the chromosomal theory of inheritance?

The genetic approach has identified single gene and multiple gene inheritance. How recessive genes can be masked in individuals. Cell biology was able to identify that chromosomes follow a pattern similar to Mendel’s laws of inheritance.