Search found 1276 matches

by Darby
Mon Mar 20, 2017 2:23 am
Forum: Evolution
Topic: subject for presentation
Replies: 1
Views: 1949

Convergent evolution would give you an opportunity to present many examples that your audience is familiar with, and connect them to how evolution is not completely random but constrained by the restrictions of a niche or lifestyle.
by Darby
Wed Mar 30, 2016 4:52 pm
Forum: Evolution
Topic: The evolution of the respiratory system
Replies: 1
Views: 2463

Most of what you're saying doesn't really make sense. Manatees have lungs, insect systems are extremely complex, gills are very good at getting oxygen from a medium that doesn't hold that much of it.
by Darby
Wed Mar 30, 2016 4:47 pm
Forum: Evolution
Topic: Where do new species come from?
Replies: 8
Views: 6310

They don't change, the POPULATION changes - changes in the environment sort through the living populations, and individuals who "fit" better, with features (adaptations) well-suited to the new conditions, tend to survive, and those adaptations become more common in the next-generation popu...
by Darby
Wed Mar 30, 2016 4:27 pm
Forum: General Discussion
Topic: How does a Virus survive
Replies: 3
Views: 2185

Viruses have casings that vary in "toughness" from one type to another - HIV doesn't do well dry, but influenza actually does better in warm, dry conditions. It will last on indoor surfaces. This is why flu season corresponds to winter-indoor season.
by Darby
Sun Jan 03, 2016 3:27 am
Forum: Human Biology
Topic: Eye color heredity
Replies: 4
Views: 3941

by Darby
Sun Jan 03, 2016 3:24 am
Forum: Human Biology
Topic: the retina and how to effect it with light
Replies: 1
Views: 1979

It depends on how you define "respond." Our ability to see edges depends upon motion. Other aspects of an object - colors and general reflectivity - shouldn't change. But we often supply the motion with tiny movements of the eyes. Focus on a printed word and really, really work at holding ...
by Darby
Thu Oct 01, 2015 5:56 pm
Forum: Evolution
Topic: Where do new species come from?
Replies: 8
Views: 6310

As variations are "selected," what changes over time is the predominant combinations of traits - with a large enough shift in conditions, and/or a decent amount of drift, your eventual "typical" individual in the population (which is, after all, what we call a "species"...
by Darby
Sun May 17, 2015 10:01 pm
Forum: Evolution
Topic: human dietry evolution since the agricultural revolution?
Replies: 11
Views: 12046

So as agriculture adjusted nutrients levels in food (not always in a predictable or single-nutrient way, there would be selection for those best able to mobilize and use those nutrients. As our diets have changed, it's likely that our abilities to best use those diets has changed as well.
by Darby
Sun May 17, 2015 9:57 pm
Forum: Zoology Discussion
Topic: Fish and its gills
Replies: 1
Views: 6236

Water does diffuse - it gets removed through the kidneys.
by Darby
Thu Apr 09, 2015 8:40 pm
Forum: Human Biology
Topic: Vitamin D absorption for different skin types
Replies: 5
Views: 7952

Re: Vitamin D absorption for different skin types

I'm not sure that a clear link between Vitamin D and depression is established - I haven't seen much attempt to control for issues like seasonal affective disorders and the like.
by Darby
Sun Mar 22, 2015 7:25 pm
Forum: Zoology Discussion
Topic: why do dogs have bigger brain than cats
Replies: 0
Views: 6307

DO dogs have proportionately bigger brains? Maybe... There are a couple of possible explanations, including the semi-literate one in your link. Sociality does seem to require some extra brain power. Another possibility may be linked to smaller dogs being bred from originally larger dogs - every aspe...
by Darby
Sun Mar 22, 2015 7:17 pm
Forum: General Discussion
Topic: What sort of jobs can one get with a biology degree ?
Replies: 5
Views: 10025

Re: What sort of jobs can one get with a biology degree ?

As you've already noted, the jobs often depend upon the specialty - virology might lead to jobs in pharmaceuticals or government bureaus. Academic careers aren't quite as limited by specialty, but they can be hard to find.