How Genes Make Flowers

Attention: open in a new window. PDFPrintE-mail

How genes make flowers, described in ScienceDaily, 10 November 2010. Scientists at the John Innes Centre and the University of East Anglia are using computer modelling and experimental genetics to work out how gene interactions control the growth of complex shapes in living things, using snapdragon flowers as an experimental model. Snapdragon (Antirrhinum) flowers have five petals that fit together to form a tube with a hinge. When a bee lands on a flower the two lower petals move on the hinge, opening the flower to allow the bee access to pollen and nectar.

The researchers looked at the effects of turning on and off four genes known to affect petal growth. They found the genes controlled both the rate and direction of growth of petal forming tissue. The orientation of growth was important. As summarised by ScienceDaily: “It is as if each cell has a chemical compass that allows it to get its bearings within the tissue, giving it the information needed to grow more in some directions than others.” The scientists have used computer modelling “to show how the flower could generate itself automatically through the application of some basic growth rules”. Enrico Coen of the John Innes Centre explained: “We are now trying to get a better understanding of exactly how the chemical compasses work and determining the molecular nature of the poles that coordinate their orientations.”

The computer model showed small changes to the growth controlling genes produced “a variety of different forms”. According to ScienceDaily: “The shape of the snapdragon flower, with the closely matched upper and lower petal shapes, could have arisen through similar 'genetic tinkering' during evolution. Evolutionary tinkering could also underlie the co-ordinated changes required for the development of many other biological structures, such as the matched upper and lower jaws of vertebrates.” Enrico Coen commented: “Looking at the complex, beautiful and finely tuned shapes produced by nature, people have often wondered how they came about. We are beginning to understand the basic genetic and chemical cues that nature uses to make them.”

ScienceDaily

Editorial Comment: Knowing how these genes work together and control growth speed and direction will help scientist understand how flowers grow into functional shapes, and it may tell us what the “basic growth rules” are, but it will not tell them where the “rules” came from. No exception is known to the principal that ‘rules’ are information applied from outside a system. They are the product of an intelligent creative designer, and they do not arise from matter randomly rattling around as would occur by “evolutionary tinkering”. Random tinkering with snapdragon flowers will only result in petals that don’t match, and therefore do not function properly when a bee lands on the flower. This means the plant would be less likely to have its pollen collected and therefore lose out in the struggle for survival. This is the real nature of mutations – devolution – not evolution. (Ref. botany, design, genetics)

Evidence News 24 Nov 2010

 

 

q_and_a2
crc_youtube
outdoor_museum_panel
free_audio2