Answer:
In biology, adaptationism is the perspective that considers that the majority of traits are optimal adaptations achieved by natural selection.
Explanation:
Among his most famous defenders are John Maynard Smith, W.D. Hamilton, Richard Dawkins and Daniel Dennett. Adaptationism has been criticized by authors such as Stephen Jay Gould and Richard Lewontin.
Stephen J. Gould summarizes the "adaptationist program" in the following arguments:
- Adaptation is the central phenomenon of evolution, and the key to understanding its mechanisms.
- Natural selection builds adaptation.
- Natural selection maintains an overwhelmingly predominant relative frequency as a cause of adaptation. Variation only provides raw material and cannot do the job without help.
<u>Characteristics of adaptationism
</u>
Gould and Lewontin (1979) summarize the following way of proceeding from the adaptationist program:
- Atomization of the organism: division of the organism into discrete and disconnected features.
- Optimization of the parts by natural selection.
- Explanation of the adaptations.
Answer:
a flower has a complex structure
Explanation:
Light rays from an object after passing through a convex lens form an image at the focal point behind the lens (opposite side of the object), What is the actual position of the object? form an image
<h2>The given statement is true</h2>
Explanation:
Iron absorption occurs in the duodenum and upper jejunum of small intestine
- At physiological pH ferrous iron is rapidly oxidized to the insoluble ferric form
- Gastric acid lowers the pH in the duodenum which enhances the solubility and uptake of ferric iron
- Once iron gets inside the enterocyte it can be stored as ferritin;Ferritin is a hollow spherical protein which helps in storage and regulation of iron levels within the body
- Ferritin molecule have ferroxidase activity which helps in the mobility of Fe2+ out of the enterocyte by ferroportin
- Transferrin is the major iron transport protein which transports iron through blood
- Fe3+ binds to transferrin so Fe2+ transported through ferroportin must be oxidized to Fe3+
- Fe2+ needs to be oxidized first so that it can be transported through ferroportin
- Once iron gets inside the cell it can be used for various cellular processes
The homology of animals is based on scientists current understanding on the evolutionary history of living species.
