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Bird-of-paradise flower pigment surprise

The ‘animal-only’ pigment bilirubin is discovered in plants


The pigment causing the orange hues of a bird-of-paradise flower sepals (main pic) is even more intense in the waxy hairs on the outside of its seed (right).

Aside from the widely recognized shape of their flowers, which resemble the head of a tropical bird, bird-of-paradise plants (Strelitzia spp.) are admired for their vibrant floral coloration. The brilliant orange is even more intense on the furry outside of their seeds, and is able to persist for decades,1 unlike most plant pigments, which degrade rapidly after cell death.


Researchers, eager to investigate the source of such long-lasting and intense colour, set about to try to identify the pigment. They used two powerful state-of-the-art laboratory techniques (high-performance liquid chromatography, and nuclear magnetic resonance) to analyze the chemical structure of the colouring agent in the bird-of-paradise plants. But the chemistry of the orange pigment didn’t match the chemical properties of any known plant pigment.

With rising excitement, the researchers realized this vivid orange was something never before identified in the plant realm. Finally, after a year of comprehensive testing, the researchers identified the orange agent as the ‘animal-only’2 pigment bilirubin.3,4,5,6 In mammals, bilirubin is a breakdown product of hemoglobin (the red pigment in blood), and is what gives the yellowish tinge to the skin of patients with jaundice or bruising. Bilirubin seems to have a useful antioxidant role.7

The finding has astonished the scientific community. What’s an ‘animal-only’ pigment doing in plants? The researchers have subsequently identified it in other flowering plants, too, showing bilirubin is not limited to the bird-of-paradise plant species.8 As yet, how plants produce bilirubin, which in animals is a product of the breakdown of blood, “is still a mystery”.4 Despite the re-think in the evolutionary storyline that this discovery necessitates, homage is paid to the evolution narrative, apparently sacrosanct whatever evidence is turned up:

“The fact that bilirubin exists in both plants and animals may demonstrate the depth of evolution. If bilirubin is synthesized via the same biochemical pathway which is responsible for producing bilirubin in animals, this would indicate that the pathway was likely conserved throughout evolutionary history in both the plant and animal kingdom.”4

Conserved throughout evolutionary history’? Only what already exists can be conserved. These knowledgeable-sounding words about “the depth of evolution” skip over the key issue—how could such complex programmed mechanisms and biochemical pathways have arisen at all during ‘evolutionary history’? The idea seems to require an imagination more vivid than the pigment.

Here’s the crux of the matter: history is recorded, not imagined,9 and the most important figure in history is on record as saying of wild flowers, His own handiwork, that “even Solomon in all his glory was not arrayed like one of these” (Luke 12:27). Of course, His message goes much deeper than that, and is open to anyone willing to escape the irrational extolling of a Creator-free existence. Surely a clear choice: the vacuous “depth of evolution” versus “the depth of the riches of wisdom and knowledge of God” (Romans 11:33).

References and notes

  1. E.g. in herbarium specimens known to have been collected at least 45 years ago. Return to text.
  2. ‘Animal’ in the biological sense of Kingdom Animalia, a categorization which includes man. Return to text.
  3. Pirone, C., and 3 others, Animal pigment bilirubin discovered in plants, Journal of the American Chemical Society 131(8):2830, 2009 | doi:10.1021/ja809065g. Return to text.
  4. Aguila, S., Florida International University scientists find animal pigment in plants,, April 2009. Return to text.
  5. First discovery of ‘animals-only’ pigment bilirubin in plants,, 23 March 2009. Return to text.
  6. Pirone, C., and 4 others, The animal pigment bilirubin identified in Strelitzia reginae, the Bird of Paradise flower, HortScience 45:1411–1415, 2010. Return to text.
  7. Sedlak, T.W. and five others, Bilirubin and glutathione have complementary antioxidant and cytoprotective roles, Proceedings of the National Academy of Sciences 106 (13):5171–5176, 31 March 2009 | doi: 10.1073/pnas.0813132106. Return to text.
  8. Pirone, C., and 4 others, Bilirubin found in diverse angiosperms, AoB PLANTS 2010:plq020 | doi:10.1093/aobpla/plq020, 28 October 2010. Return to text.
  9. See, e.g., Science, history and the Bible,, 28 July 2012. Return to text.

Helpful Resources

By Design
by Dr Jonathan Sarfati
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Readers’ comments

Anthony W.
I think you'll find that the flower resembles a whole bird - consider the lead photo in this article. The 'bird' is flying from right to left.
Michael S.
‘Conserved throughout evolutionary history’? How would a feature such as this arise spontaneously (and, as they would have us believe, randomly) in two completely different organisms? The odds against such an 'evolutionary' pathway are insurmountable, and yet randomness, they insist, has been the driving mechanism behind untold hundreds of thousands of biological changes across millions of (known) species.

The faith that it would require to believe something like that is incredible.
James K.
Plants and animals supposedly last shared a common ancestor before algae evolved (something they think resembles euglena) and consequently before blood evolved. What the evolutionists are saying is truly absurd. They should just say it’s a case of homoplasy. Increasingly absurd beliefs are being framed as science. This sets a very grim picture for the future of scientific thought.
Dan M.
Yes, to an informed individual, all of nature is apparently, obviously, designed! We are immune to evolutionary indoctrination.
We human beings design many complex things like computers and 747's. Not comparable to Gods creation but complex non the less by earthly standards. When was the last time you saw any other earthly creature design anything remotely complex? Other than humans it doesn't happen. That is why the bible says in Genesis 1:27, we, (man) are created in Gods image and are the only earthly creatures capable of abstract thought and design as He is.
All the honor and glory belongs to GOD.
Stephen L.
Hemoglobin in animals and Chrorophyll in plants contain a porphyrin at their core the difference being a magnesium at the center in plants and an iron atom at the center in animals. So bilirubin from the porphyrin is not too surprising. What is surprising is how complicated it is to get the porphyrin in the first place ([link deleted per feedback rules]. This wonderful molecule Porphyrin is at the center of life.
Don Batten
In vertebrates, two complex enzymes are needed to convert haem/heme (a porphyrin with an iron atom in the middle of the ring structure), into bilirubin, which does not have the iron or a ring structure. The biochemical pathway for the production of bilirubin in plants is not known, but if it is derived from chlorophyll, it would require somewhat different enzymes.
As the article points out, evolutionists want to argue that the biochemistry has been conserved through deep time (from the imagined common ancestor that supposedly gave rise to both animals and plants), which, considering how many mutations would have occurred over the many humdreds of millions of evolutionary years, is a rather grand claim to say the least.
WillyT T.
Since bilirubin has been found in both animals and plants, does not the evolutionists' explanation using the so called "depth of evolution" and "the pathway of evolution" logically imply that at some point in time, humans evolved from plants? This adds a completely new dimension to the evolutionary chart.
Don Batten
Well, they have always claimed that we had a common ancestor with plants.
Denese K.
This is a very interesting and exciting discovery. It may explain something that has troubled me for some time. I have Strelitzia regina var. "Mandela's Gold" (the yellow hybrid) growing in my garden. At its first flowering, it put out copious double-blooms, but since then it has been decimated by vervet monkeys any time a new "bud" appears. (The bud being the long boat-shaped base) Never again have any flowers been permitted to grow - the vervets eat the bud back to the stalk. All of the strelitzias are known for their copious nectar, but perhaps it is this bilirubin within the plant that appeals to the monkeys (being omnivores). I would be very interested to know if the blue pigment has any similar feature.
Don Batten
An interesting observation about the vervet monkey liking for Strelitzias. A friend here in Australia has a problem with possums eating the buds of magnolias before they open.
I doubt that they would be eating them for the bilirubin because it is a waste product of hemoglobin breakdown in vertebrates, with a fairly elaborate system for excreting it from the body. If it builds up, it is toxic. That is, it is not a nutrient.
WillyY T.
New to me Don. So why does not the everyday reader hear of this? Sounds even more incredulous but almost plausible humans could come from primates but completely implausible from plants. The evidence must even thinner that it is for primate to human evidence
Don Batten
The big picture, Grand Theory of Evolution entails the origin of all the diversity of life from a single chance origin of a single celled organism. See Familiarity breeds respect?
Mark F.
The comments are missing something important. This case is NOT pointing to some common ancester. Bilirubin is the breakdown product of hemeglobin, the oxygen carrying molecule in multi-cell animals that have a circulatory system. It is not present in simpler cases, because amoeba or algae can get their oxygen directly from the environment. Besides, having two different sources for bilirubin is not an argument for common ancester; rather it would have to be explained by "convergent evolution", which is one of the catch-all explanations by evolutionists for things they cannot explain.

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