Smarty Plants

How can organisms stuck in the soil do so many amazing tricks?

Tricky trap: The parachute flower has a “cunning strategy” to lure its pollinator to come in for a visit, Science Daily says. First, it emits the odor of the fly’s favorite feast, dying honeybees (about like a sizzling roast smells for a human). Then, it traps the fly inside for about 24 hours, long enough to ensure pollination. But it doesn’t pay off. The fly gets nothing. Is this deception? Is it a scam? Hey, flowers are not free moral agents.

Birth control: Many plants cast their seeds with a good aim, says PhysOrg. Whether they live in the water, at the shoreline, or on the land, they “actively direct their seeds via wind or water towards suitable sites.” To achieve “directed dispersal,” some attach their seeds to animals that will carry them far away. Others make use of wind or water to distribute the seeds. For instance, plants that live in usually flooded areas produce seeds that sink immediately. If there are only scattered ponds, though, “Plants growing on the uplands have seeds that are best dispersed by wind, facilitating their transportation across wet areas to reach other dry sites.” The expectation of design led one scientist to an intelligent discovery.

Whereas directed dispersal has been known for animal-dispersed plant species, most plant species are not dispersed by animals but by water or wind. “I wondered: wouldn’t it be highly efficient for these species as well, if their seeds were dispersed predominantly towards suitable sites?” says Merel Soons, lead author of the publication. Together with her research team, she studied a range of wetland plant species growing in the water, on shorelines, and on the permanently dry, upland part. “We were excited to discover that these plants can direct their own seeds via wind or water,” says Soons. “It appears that plants are really quite ‘smart’.“

The flatness problem: As opposed to stems, most leaves are flat. This enables them to expose the maximum surface area to the sun for photosynthesis. Look at what goes into making a flat leaf, as described in a press release from EMBL, the European Molecular Biology Laboratory:

How does a set of plant cells grow from a bump into a flat leaf that can efficiently capture sunlight? In a paper published this week in PNAS, EMBL scientists show how different types of molecules on the top and bottom of a leaf keep each other in check, ensuring the leaf grows flat.

The process involves micro-RNAs and proteins designated Class II and Class III arranged differently on the tops and bottoms of the growing bump. How this works exactly, though, will take more research.

“The activities of the Class III HD-ZIPs and microRNAs somehow have to be perfectly balanced, right from the beginning, to get a nice leaf,” says Heisler.  “And that seems unlikely to happen on its own: so what’s maintaining this balance?”

Heisler and colleagues are following up on the work, looking into how the balance between ‘top’ and ‘bottom’ factors is maintained, honing in on exactly how Class IIIs and Class IIs work together, and investigating other molecules that are restricted to only one side of a growing leaf.

Why autumn leaves? They’re beautiful, no question about it. But why do leaves change color in the fall? PhysOrg explores the biology and ecology of autumn leaves. They don’t really change color; they unmask it, Jeff Atkins explains. Green chlorophyll depletes after summer, leaving the reds, oranges and yellows that were there all along. An “abscission layer” forms that prevents new chlorophyll from growing. It’s all a matter of balancing energy requirements with nutrient availability. Also, “Enzymes within the leaves will not work at low or high temperatures,” he says. So the chlorophyll must go, and the leaves must drop. One thing Atkins doesn’t explain is why people find the color transformation so beautiful.

Fall colors in Colorado (photo by David Coppedge)

The facts of nature such as we see above should be sources of endless fascination and joy. The Teaching Company offers a course on “The Joy of Science” by Robert Hazen of George Mason University. Hazen is an excellent teacher, but he is a Darwinian and probably a materialist (since he also offers a course arguing that the origin of life happened spontaneously by strictly chemical and physical processes). But how can he be joyful about science? What is to enjoy if everything is an accident of mindless processes? It would be like teaching about “The Joy of ‘Stuff Happens‘.”

The only way he can claim joy is to borrow from the Christian worldview that teaches humans are made in the image of God. We don’t deny that Dr. Hazen feels joy, because we understand him to be a member of the class of creatures God blessed with that capacity. We would say, though, that he cannot account for the joy he feels from his own worldview assumptions.

An old Christian chorus says with childlike simplicity, “If you want joy, real joy, wonderful joy, let Jesus come into your heart.” Paul told the anxious Philippian jailer, “Believe on the Lord Jesus Christ, and you will be saved.” The jailer did. What was the reaction? “he rejoiced along with his entire household that he had believed in God” (Acts 16:16-34). Paul later told the whole Philippian church that he had founded, “Rejoice in the Lord always; again I say, rejoice” (Philippians 4:4). Joy is a Christian blessing above and beyond becoming saved from sin. Joy is an over-the-top gift of God’s grace, just as the colors of this amazing world and all its living designs far surpass the minimum requirements of habitability. Believe in Christ to experience real joy. Then, every flower, every leaf, every color in God’s green earth will be a stimulus for wonderful joy.