This morning, after a walk, a light breakfast and another walk I got home asking myself, "How are complex behaviours (like a spider spinning a web) transmitted from parent to offspring?" I mean how does a baby spider grow up and just know that it has to spin a web in order to catch insects to eat and just know how to spin that web? And does the grown up spider know these things? Is knowledge involved or Is spinning a web an autonomic activity like breathing? In any event how are such complex behaviours passed on from generation to generation? I assumed the method was genetic with evolution and millions of years involved.
I searched online with "how are complex behaviours transmitted genetically" and got this page of articles several of which I will dip into. I chose first the NIH Guide: GENETIC BASIS OF COMPLEX BEHAVIORS and started with the two paragraphs below headed "Research Objectives". I enoy reading this kind of stuff even
though I don't understand it all and have to go back over sections and
look up technical terms in the dictionary and take regular breaks before
my head explodes. We'll never know everything (those who claim to have an answer for everything are liars) but I enjoy wrestling with existance.
Extensive scientific evidence supports a substantial genetic contribution to complex behaviors in humans and animals, but the nature of that contribution is still poorly understood. Recently, preliminary evidence has been presented for the chromosomal localization of genes for learning, emotionality, and abnormal sensorimotor gating in mice. This success provides further impetus to the search for the genes and mechanisms that contribute to normal and abnormal complex behaviors in animals and to complex behaviors of relevance to human health and disease. Through identification of genes underlying complex behavioral traits that are also expressed in mental disorders, further insight into the genetic basis of mental disorders as well as of complex behaviors may be obtained.
To identify specific genes underlying complex behavioral traits, more research is needed on the role of quantitative trait loci (QTLs) as well as of single genes of major effect and the environmental factors that correlate or interact with them. Genetic technologies have progressed rapidly, permitting a parallel expansion of research. Our increasing ability to manipulate the genome in experimental organisms has created new scientific opportunities to understand the development of the genetics of complex behavior.
One important approach in experimental organisms is random mutagenesis followed by screening for impairments in behavioral phenotypes. Another important approach is the generation of null mutations or "knock-outs" using gene targeting technologies with the goal of identification of novel behavioral mutations. Ongoing refinements of transgenic techniques for turning genes on or off in vivo (in specific cell types and/or stages of development) as well as technological refinements in measuring how these genetic alterations affect function in vivo are creating new opportunities to investigate interactions between genes, brain, and behavior. However, progress in behavioral genetic research in animals is impeded by many technical barriers which need to be addressed. For example, in the mouse, genetic mutations are being created in a limited number of strains (those whose embryonic stem (ES) cells can be easily propagated in germ line), some of which have typical, if not aberrant, neurobehavioral phenotypes. The effects of many of the mutations being created are developmentally and regionally nonspecific and therefore difficult to interpret.